# Supplementary Material (ESI) for New Journal of Chemistry # This journal is © The Royal Society of Chemistry and # The Centre National de la Recherche Scientifique, 2009 data_global _journal_coden_Cambridge 440 loop_ _publ_author_name 'Wilson, Chick' 'Adam, Martin' 'Gutmann, Matthias' 'Leech, Charlotte' 'Middlemiss, Derek' 'Parkin, Andrew' 'Thomas, Lynne' _publ_contact_author_name 'Chick Wilson' _publ_contact_author_email chick@chem.gla.ac.uk _publ_section_title ; Stability and cooperativity of hydrogen bonds in dihydroxybenzoic acids ; data_25dhoba100kxray _database_code_depnum_ccdc_archive 'CCDC 747937' _chemical_name_systematic '2,5-dihydroxybenzoic acid' _chemical_melting_point ? _cell_length_a 5.5591(2) _cell_length_b 4.8698(2) _cell_length_c 23.3593(9) _cell_angle_alpha 90 _cell_angle_beta 93.448(2) _cell_angle_gamma 90 _cell_volume 631.23(4) _symmetry_cell_setting Monoclinic _symmetry_space_group_name_H-M 'P 1 21/n 1 ' _symmetry_space_group_name_Hall ? loop_ _symmetry_equiv_pos_as_xyz 'x, y, z' '-x+1/2, y+1/2, -z+1/2' '-x, -y, -z' 'x-1/2, -y-1/2, z-1/2' _cell_formula_units_Z 4 # Given Formula = C7 H6 O4 # Dc = 1.62 Fooo = 320.00 Mu = 1.36 M = 154.12 # Found Formula = C7 H6 O4 # Dc = 1.62 FOOO = 320.00 Mu = 1.36 M = 154.12 _chemical_formula_sum 'C7 H6 O4' _chemical_formula_moiety 'C7 H6 O4' _chemical_compound_source ? _chemical_formula_weight 154.12 _cell_measurement_reflns_used 0 _cell_measurement_theta_min 0 _cell_measurement_theta_max 0 _cell_measurement_temperature 100 _exptl_crystal_description block _exptl_crystal_colour clear _exptl_crystal_size_min ? _exptl_crystal_size_mid ? _exptl_crystal_size_max ? _exptl_crystal_density_diffrn 1.622 _exptl_crystal_density_method 'not measured' _exptl_crystal_F_000 320 _exptl_absorpt_coefficient_mu 0.135 _exptl_absorpt_correction_type none _diffrn_measurement_device_type 'Nonius KappaCCD' _diffrn_radiation_monochromator graphite _diffrn_radiation_type 'Mo K\a' _diffrn_radiation_wavelength 0.71073 _diffrn_measurement_method '\f & \w scans' _computing_data_collection 'COLLECT (Nonius, 1997-2001).' _computing_cell_refinement 'DENZO/SCALEPACK (Otwinowski & Minor, 1997)' _computing_data_reduction 'DENZO/SCALEPACK (Otwinowski & Minor, 1997)' _computing_structure_solution 'SIR92 (Altomare et al., 1994)' _computing_structure_refinement 'SHELXL-97 (Sheldrick, 2008)' _computing_molecular_graphics 'ORTEP (Farrugia, 1997), Mercury (McRae, 2006)' _exptl_special_details ; ? ; _diffrn_ambient_temperature 100(2) _diffrn_reflns_number 10859 _diffrn_reflns_av_R_equivalents 0.0724 _diffrn_reflns_av_unetI/netI 0.0367 _diffrn_reflns_theta_min 1.75 _diffrn_reflns_theta_max 27.56 _diffrn_reflns_theta_full 27.56 _diffrn_measured_fraction_theta_max 0.997 _diffrn_measured_fraction_theta_full 0.997 _diffrn_reflns_limit_h_min -7 _diffrn_reflns_limit_h_max 7 _diffrn_reflns_limit_k_min -6 _diffrn_reflns_limit_k_max 6 _diffrn_reflns_limit_l_min -27 _diffrn_reflns_limit_l_max 30 #============================================================================== # STRUCTURE SOLUTION _atom_sites_solution_primary direct _atom_sites_solution_secondary difmap _atom_sites_solution_hydrogens difmap #============================================================================== # REFINEMENT DATA _refine_special_details ; Refinement of F^2^ against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F^2^, conventional R-factors R are based on F, with F set to zero for negative F^2^. The threshold expression of F^2^ > 2\s(F^2^) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F^2^ are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger. ; _reflns_number_total 1463 _reflns_number_gt 1064 _reflns_threshold_expression >2\s(I) _refine_ls_structure_factor_coef Fsqd _refine_ls_matrix_type full _refine_ls_R_factor_all 0.0674 _refine_ls_R_factor_gt 0.043 _refine_ls_wR_factor_ref 0.1284 _refine_ls_goodness_of_fit_ref 0.867 _refine_ls_restrained_S_all 0.867 _refine_ls_number_reflns 1463 _refine_ls_number_parameters 124 _refine_ls_number_restraints 0 _refine_ls_hydrogen_treatment refall _refine_ls_weighting_scheme calc _refine_ls_weighting_details 'calc w=1/[\s^2^(Fo^2^)+(0.0666P)^2^+1.0576P] where P=(Fo^2^+2Fc^2^)/3' _refine_ls_shift/su_max 0 _refine_ls_shift/su_mean 0 _refine_diff_density_max 0.263 _refine_diff_density_min -0.328 _refine_diff_density_rms 0.063 _refine_ls_extinction_method none loop_ _atom_type_symbol _atom_type_description _atom_type_scat_dispersion_real _atom_type_scat_dispersion_imag _atom_type_scat_source C C 0.0033 0.0016 'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4' H H 0 0 'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4' O O 0.0106 0.006 'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4' #============================================================================== # ATOMIC COORDINATES AND DISPLACEMENT PARAMETERS loop_ _atom_site_label _atom_site_fract_x _atom_site_fract_y _atom_site_fract_z _atom_site_U_iso_or_equiv _atom_site_adp_type _atom_site_calc_flag _atom_site_refinement_flags _atom_site_occupancy _atom_site_disorder_assembly _atom_site_disorder_group _atom_site_type_symbol C1 0.0841(3) 0.5113(4) 0.10422(8) 0.0142(4) Uani d . 1 . . C C2 0.2887(4) 0.3454(4) 0.10072(8) 0.0155(4) Uani d . 1 . . C C3 0.3399(4) 0.1446(4) 0.14278(9) 0.0168(4) Uani d . 1 . . C C4 0.1919(4) 0.1138(4) 0.18748(8) 0.0159(4) Uani d . 1 . . C C5 -0.0109(3) 0.2810(4) 0.19138(8) 0.0136(4) Uani d . 1 . . C C6 -0.0669(3) 0.4774(4) 0.14995(8) 0.0141(4) Uani d . 1 . . C C7 0.0314(4) 0.7232(4) 0.06015(8) 0.0149(4) Uani d . 1 . . C O9 -0.1651(3) 0.8689(3) 0.06590(6) 0.0181(3) Uani d . 1 . . O O8 0.1656(3) 0.7590(3) 0.02039(6) 0.0201(4) Uani d . 1 . . O O2 0.4426(3) 0.3671(3) 0.05804(6) 0.0217(4) Uani d . 1 . . O O5 -0.1502(3) 0.2422(3) 0.23802(6) 0.0170(3) Uani d . 1 . . O H3 0.488(5) 0.027(5) 0.1395(10) 0.026(6) Uiso d . 1 . . H H4 0.231(4) -0.018(5) 0.2175(10) 0.024(6) Uiso d . 1 . . H H6 -0.209(5) 0.596(5) 0.1509(10) 0.026(6) Uiso d . 1 . . H H1 -0.180(5) 0.990(7) 0.0362(14) 0.053(9) Uiso d . 1 . . H H5 -0.230(5) 0.391(6) 0.2432(12) 0.031(7) Uiso d . 1 . . H H2 0.389(5) 0.512(7) 0.0364(13) 0.042(8) Uiso d . 1 . . H loop_ _atom_site_aniso_label _atom_site_aniso_U_11 _atom_site_aniso_U_22 _atom_site_aniso_U_33 _atom_site_aniso_U_12 _atom_site_aniso_U_13 _atom_site_aniso_U_23 C1 0.0170(9) 0.0134(9) 0.0121(9) -0.0011(8) 0.0006(7) -0.0007(7) C2 0.0160(9) 0.0169(10) 0.0137(9) -0.0020(8) 0.0027(7) -0.0010(7) C3 0.0145(9) 0.0171(10) 0.0188(10) 0.0023(8) -0.0001(7) -0.0008(8) C4 0.0196(10) 0.0147(10) 0.0130(9) -0.0011(8) -0.0020(7) 0.0010(7) C5 0.0156(9) 0.0138(9) 0.0117(9) -0.0032(7) 0.0025(7) -0.0021(7) C6 0.0157(9) 0.0139(9) 0.0127(9) 0.0002(7) 0.0008(7) -0.0011(7) C7 0.0187(10) 0.0147(9) 0.0116(9) -0.0025(8) 0.0013(7) -0.0012(7) O9 0.0207(7) 0.0177(7) 0.0160(7) 0.0034(6) 0.0025(5) 0.0050(6) O8 0.0259(8) 0.0193(8) 0.0158(7) 0.0016(6) 0.0067(6) 0.0036(6) O2 0.0197(7) 0.0263(8) 0.0201(8) 0.0046(6) 0.0102(6) 0.0062(7) O5 0.0220(8) 0.0147(7) 0.0148(7) 0.0022(6) 0.0068(5) 0.0025(6) #============================================================================== # MOLECULAR GEOMETRY _geom_special_details ; All s.u.'s (except the s.u. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell s.u.'s are taken into account individually in the estimation of s.u.'s in distances, angles and torsion angles; correlations between s.u.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell s.u.'s is used for estimating s.u.'s involving l.s. planes. ; loop_ _geom_bond_atom_site_label_1 _geom_bond_atom_site_label_2 _geom_bond_site_symmetry_2 _geom_bond_distance _geom_bond_publ_flag C1 C2 . 1.402(3) ? C1 C6 . 1.407(3) ? C1 C7 . 1.475(3) ? C2 O2 . 1.356(2) ? C2 C3 . 1.403(3) ? C3 C4 . 1.376(3) ? C3 H3 . 1.01(3) ? C4 C5 . 1.398(3) ? C4 H4 . 0.97(3) ? C5 C6 . 1.383(3) ? C5 O5 . 1.387(2) ? C6 H6 . 0.98(3) ? C7 O8 . 1.238(2) ? C7 O9 . 1.316(2) ? O9 H1 . 0.91(3) ? O2 H2 . 0.91(3) ? O5 H5 . 0.86(3) ? loop_ _geom_angle_atom_site_label_1 _geom_angle_atom_site_label_2 _geom_angle_atom_site_label_3 _geom_angle _geom_angle_site_symmetry_1 _geom_angle_site_symmetry_3 _geom_angle_publ_flag C2 C1 C6 119.99(17) . . ? C2 C1 C7 119.38(17) . . ? C6 C1 C7 120.63(17) . . ? O2 C2 C1 123.22(18) . . ? O2 C2 C3 117.31(18) . . ? C1 C2 C3 119.48(18) . . ? C4 C3 C2 120.14(18) . . ? C4 C3 H3 121.5(14) . . ? C2 C3 H3 118.4(14) . . ? C3 C4 C5 120.47(18) . . ? C3 C4 H4 120.2(14) . . ? C5 C4 H4 119.3(14) . . ? C6 C5 O5 122.08(17) . . ? C6 C5 C4 120.39(18) . . ? O5 C5 C4 117.53(17) . . ? C5 C6 C1 119.53(18) . . ? C5 C6 H6 122.8(15) . . ? C1 C6 H6 117.7(15) . . ? O8 C7 O9 122.81(18) . . ? O8 C7 C1 121.26(18) . . ? O9 C7 C1 115.93(17) . . ? C7 O9 H1 108(2) . . ? C2 O2 H2 105.5(18) . . ? C5 O5 H5 108.2(18) . . ? loop_ _geom_torsion_atom_site_label_1 _geom_torsion_atom_site_label_2 _geom_torsion_atom_site_label_3 _geom_torsion_atom_site_label_4 _geom_torsion _geom_torsion_site_symmetry_1 _geom_torsion_site_symmetry_2 _geom_torsion_site_symmetry_3 _geom_torsion_site_symmetry_4 _geom_torsion_publ_flag C6 C1 C2 O2 -179.76(18) . . . . ? C7 C1 C2 O2 -0.7(3) . . . . ? C6 C1 C2 C3 0.6(3) . . . . ? C7 C1 C2 C3 179.67(18) . . . . ? O2 C2 C3 C4 179.43(18) . . . . ? C1 C2 C3 C4 -0.9(3) . . . . ? C2 C3 C4 C5 0.2(3) . . . . ? C3 C4 C5 C6 0.8(3) . . . . ? C3 C4 C5 O5 -178.97(17) . . . . ? O5 C5 C6 C1 178.66(17) . . . . ? C4 C5 C6 C1 -1.1(3) . . . . ? C2 C1 C6 C5 0.4(3) . . . . ? C7 C1 C6 C5 -178.68(18) . . . . ? C2 C1 C7 O8 -0.6(3) . . . . ? C6 C1 C7 O8 178.43(18) . . . . ? C2 C1 C7 O9 179.30(17) . . . . ? C6 C1 C7 O9 -1.6(3) . . . . ? data_25dhoba150kxray _database_code_depnum_ccdc_archive 'CCDC 747938' _chemical_name_systematic '2,5-dihydroxybenzoic acid' _chemical_melting_point ? _cell_length_a 5.5751(2) _cell_length_b 4.8787(2) _cell_length_c 23.4030(9) _cell_angle_alpha 90 _cell_angle_beta 93.223(2) _cell_angle_gamma 90 _cell_volume 635.54(4) _symmetry_cell_setting Monoclinic _symmetry_space_group_name_H-M 'P 1 21/n 1 ' _symmetry_space_group_name_Hall ? loop_ _symmetry_equiv_pos_as_xyz 'x, y, z' '-x+1/2, y+1/2, -z+1/2' '-x, -y, -z' 'x-1/2, -y-1/2, z-1/2' _cell_formula_units_Z 4 _chemical_formula_sum 'C7 H6 O4' _chemical_formula_moiety 'C7 H6 O4' _chemical_compound_source ? _chemical_formula_weight 154.12 _cell_measurement_reflns_used 0 _cell_measurement_theta_min 0 _cell_measurement_theta_max 0 _cell_measurement_temperature 150(2) _exptl_crystal_description block _exptl_crystal_colour clear _exptl_crystal_size_min ? _exptl_crystal_size_mid ? _exptl_crystal_size_max ? _exptl_crystal_density_diffrn 1.611 _exptl_crystal_density_method 'not measured' _exptl_crystal_F_000 320 _exptl_absorpt_coefficient_mu 0.135 _exptl_absorpt_correction_type none _diffrn_measurement_device_type 'Nonius KappaCCD' _diffrn_radiation_monochromator graphite _diffrn_radiation_type 'Mo K\a' _diffrn_radiation_wavelength 0.71073 _diffrn_measurement_method '\f & \w scans' _computing_data_collection 'COLLECT (Nonius, 1997-2001).' _computing_cell_refinement 'DENZO/SCALEPACK (Otwinowski & Minor, 1997)' _computing_data_reduction 'DENZO/SCALEPACK (Otwinowski & Minor, 1997)' _computing_structure_solution 'SIR92 (Altomare et al., 1994)' _computing_structure_refinement 'SHELXL-97 (Sheldrick, 2008)' _computing_molecular_graphics 'ORTEP (Farrugia, 1997), Mercury (McRae, 2006)' _exptl_special_details ; ? ; _diffrn_ambient_temperature 150(2) _diffrn_reflns_number 12380 _diffrn_reflns_av_R_equivalents 0.0817 _diffrn_reflns_av_unetI/netI 0.0511 _diffrn_reflns_theta_min 1.74 _diffrn_reflns_theta_max 30.01 _diffrn_reflns_theta_full 30.01 _diffrn_measured_fraction_theta_max 0.997 _diffrn_measured_fraction_theta_full 0.997 _diffrn_reflns_limit_h_min -7 _diffrn_reflns_limit_h_max 7 _diffrn_reflns_limit_k_min -6 _diffrn_reflns_limit_k_max 6 _diffrn_reflns_limit_l_min -28 _diffrn_reflns_limit_l_max 32 #============================================================================== # STRUCTURE SOLUTION _atom_sites_solution_primary direct _atom_sites_solution_secondary difmap _atom_sites_solution_hydrogens difmap #============================================================================== # REFINEMENT DATA _refine_special_details ; Refinement of F^2^ against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F^2^, conventional R-factors R are based on F, with F set to zero for negative F^2^. The threshold expression of F^2^ > 2\s(F^2^) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F^2^ are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger. ; _reflns_number_total 1850 _reflns_number_gt 1168 _reflns_threshold_expression >2\s(I) _refine_ls_structure_factor_coef Fsqd _refine_ls_matrix_type full _refine_ls_R_factor_all 0.0972 _refine_ls_R_factor_gt 0.0494 _refine_ls_wR_factor_ref 0.1371 _refine_ls_goodness_of_fit_ref 1.039 _refine_ls_restrained_S_all 1.039 _refine_ls_number_reflns 1850 _refine_ls_number_parameters 124 _refine_ls_number_restraints 0 _refine_ls_hydrogen_treatment refall _refine_ls_weighting_scheme calc _refine_ls_weighting_details 'calc w=1/[\s^2^(Fo^2^)+(0.0579P)^2^+0.3338P] where P=(Fo^2^+2Fc^2^)/3' _refine_ls_shift/su_max 0 _refine_ls_shift/su_mean 0 _refine_diff_density_max 0.309 _refine_diff_density_min -0.331 _refine_diff_density_rms 0.069 _refine_ls_extinction_method none loop_ _atom_type_symbol _atom_type_description _atom_type_scat_dispersion_real _atom_type_scat_dispersion_imag _atom_type_scat_source C C 0.0033 0.0016 'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4' H H 0 0 'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4' O O 0.0106 0.006 'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4' #============================================================================== # ATOMIC COORDINATES AND DISPLACEMENT PARAMETERS loop_ _atom_site_label _atom_site_fract_x _atom_site_fract_y _atom_site_fract_z _atom_site_U_iso_or_equiv _atom_site_adp_type _atom_site_calc_flag _atom_site_refinement_flags _atom_site_occupancy _atom_site_disorder_assembly _atom_site_disorder_group _atom_site_type_symbol C1 0.0848(3) 0.5135(4) 0.10437(7) 0.0174(4) Uani d . 1 . . C C2 0.2883(3) 0.3486(4) 0.10088(8) 0.0197(4) Uani d . 1 . . C O2 0.4421(3) 0.3693(3) 0.05809(6) 0.0291(4) Uani d . 1 . . O C3 0.3389(3) 0.1486(4) 0.14289(8) 0.0214(4) Uani d . 1 . . C C4 0.1917(3) 0.1188(4) 0.18747(8) 0.0197(4) Uani d . 1 . . C C5 -0.0108(3) 0.2851(4) 0.19140(7) 0.0176(4) Uani d . 1 . . C O5 -0.1503(3) 0.2466(3) 0.23807(5) 0.0217(3) Uani d . 1 . . O C6 -0.0657(3) 0.4804(4) 0.15005(7) 0.0172(4) Uani d . 1 . . C C7 0.0324(3) 0.7239(4) 0.06020(7) 0.0190(4) Uani d . 1 . . C O8 0.1658(3) 0.7598(3) 0.02041(6) 0.0262(4) Uani d . 1 . . O O9 -0.1635(2) 0.8702(3) 0.06597(6) 0.0234(3) Uani d . 1 . . O H3 0.493(4) 0.037(5) 0.1397(10) 0.037(7) Uiso d . 1 . . H H4 0.233(4) -0.017(5) 0.2167(9) 0.023(5) Uiso d . 1 . . H H6 -0.208(4) 0.600(5) 0.1510(9) 0.022(5) Uiso d . 1 . . H H5 -0.233(5) 0.398(6) 0.2443(11) 0.047(8) Uiso d . 1 . . H H1 -0.174(5) 0.998(7) 0.0352(12) 0.062(9) Uiso d . 1 . . H H2 0.386(5) 0.513(7) 0.0366(12) 0.056(9) Uiso d . 1 . . H loop_ _atom_site_aniso_label _atom_site_aniso_U_11 _atom_site_aniso_U_22 _atom_site_aniso_U_33 _atom_site_aniso_U_12 _atom_site_aniso_U_13 _atom_site_aniso_U_23 C1 0.0229(9) 0.0168(9) 0.0128(8) -0.0018(7) 0.0028(6) -0.0001(7) C2 0.0203(9) 0.0223(10) 0.0167(8) -0.0011(8) 0.0039(7) -0.0017(7) O2 0.0272(8) 0.0347(9) 0.0269(8) 0.0062(7) 0.0148(6) 0.0067(7) C3 0.0203(9) 0.0223(10) 0.0214(9) 0.0017(8) -0.0004(7) -0.0004(8) C4 0.0237(9) 0.0178(9) 0.0172(9) 0.0004(8) -0.0022(7) 0.0013(7) C5 0.0210(9) 0.0182(9) 0.0138(8) -0.0034(7) 0.0036(6) -0.0004(7) O5 0.0290(8) 0.0197(7) 0.0173(6) 0.0015(6) 0.0089(5) 0.0031(5) C6 0.0187(9) 0.0166(9) 0.0165(8) 0.0010(7) 0.0020(6) -0.0002(7) C7 0.0239(9) 0.0179(9) 0.0153(8) -0.0011(7) 0.0018(7) 0.0006(7) O8 0.0316(8) 0.0274(8) 0.0205(7) 0.0025(6) 0.0105(6) 0.0075(6) O9 0.0273(7) 0.0224(7) 0.0208(7) 0.0041(6) 0.0044(5) 0.0073(6) #============================================================================== # MOLECULAR GEOMETRY _geom_special_details ; All s.u.'s (except the s.u. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell s.u.'s are taken into account individually in the estimation of s.u.'s in distances, angles and torsion angles; correlations between s.u.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell s.u.'s is used for estimating s.u.'s involving l.s. planes. ; loop_ _geom_bond_atom_site_label_1 _geom_bond_atom_site_label_2 _geom_bond_site_symmetry_2 _geom_bond_distance _geom_bond_publ_flag C1 C2 . 1.397(3) ? C1 C6 . 1.405(2) ? C1 C7 . 1.474(2) ? C2 O2 . 1.358(2) ? C2 C3 . 1.402(3) ? O2 H2 . 0.91(3) ? C3 C4 . 1.371(3) ? C3 H3 . 1.02(2) ? C4 C5 . 1.397(3) ? C4 H4 . 0.97(2) ? C5 C6 . 1.380(2) ? C5 O5 . 1.389(2) ? O5 H5 . 0.89(3) ? C6 H6 . 0.99(2) ? C7 O8 . 1.236(2) ? C7 O9 . 1.318(2) ? O9 H1 . 0.95(3) ? loop_ _geom_angle_atom_site_label_1 _geom_angle_atom_site_label_2 _geom_angle_atom_site_label_3 _geom_angle _geom_angle_site_symmetry_1 _geom_angle_site_symmetry_3 _geom_angle_publ_flag C2 C1 C6 119.99(16) . . ? C2 C1 C7 119.30(16) . . ? C6 C1 C7 120.70(16) . . ? O2 C2 C1 123.28(17) . . ? O2 C2 C3 117.26(17) . . ? C1 C2 C3 119.46(16) . . ? C2 O2 H2 104.7(18) . . ? C4 C3 C2 120.12(18) . . ? C4 C3 H3 122.6(13) . . ? C2 C3 H3 117.2(13) . . ? C3 C4 C5 120.58(17) . . ? C3 C4 H4 118.8(12) . . ? C5 C4 H4 120.6(12) . . ? C6 C5 O5 122.19(17) . . ? C6 C5 C4 120.20(16) . . ? O5 C5 C4 117.62(16) . . ? C5 O5 H5 109.6(18) . . ? C5 C6 C1 119.64(17) . . ? C5 C6 H6 122.6(12) . . ? C1 C6 H6 117.7(12) . . ? O8 C7 O9 122.52(17) . . ? O8 C7 C1 121.54(17) . . ? O9 C7 C1 115.94(16) . . ? C7 O9 H1 107.1(18) . . ? loop_ _geom_torsion_atom_site_label_1 _geom_torsion_atom_site_label_2 _geom_torsion_atom_site_label_3 _geom_torsion_atom_site_label_4 _geom_torsion _geom_torsion_site_symmetry_1 _geom_torsion_site_symmetry_2 _geom_torsion_site_symmetry_3 _geom_torsion_site_symmetry_4 _geom_torsion_publ_flag C6 C1 C2 O2 -179.83(17) . . . . ? C7 C1 C2 O2 -0.7(3) . . . . ? C6 C1 C2 C3 0.7(3) . . . . ? C7 C1 C2 C3 179.85(17) . . . . ? O2 C2 C3 C4 179.46(18) . . . . ? C1 C2 C3 C4 -1.0(3) . . . . ? C2 C3 C4 C5 0.5(3) . . . . ? C3 C4 C5 C6 0.5(3) . . . . ? C3 C4 C5 O5 -179.13(17) . . . . ? O5 C5 C6 C1 178.77(16) . . . . ? C4 C5 C6 C1 -0.8(3) . . . . ? C2 C1 C6 C5 0.2(3) . . . . ? C7 C1 C6 C5 -178.91(17) . . . . ? C2 C1 C7 O8 -0.7(3) . . . . ? C6 C1 C7 O8 178.42(17) . . . . ? C2 C1 C7 O9 179.42(16) . . . . ? C6 C1 C7 O9 -1.4(2) . . . . ? _diffrn_standards_interval_time ? _diffrn_standards_interval_count ? _diffrn_standards_number 0 _diffrn_standards_decay_% ? data_25dhoba200kxray _database_code_depnum_ccdc_archive 'CCDC 747939' _chemical_name_systematic '2,5-dihydroxybenzoic acid' _chemical_melting_point ? _cell_length_a 5.5929(3) _cell_length_b 4.8891(2) _cell_length_c 23.4513(9) _cell_angle_alpha 90 _cell_angle_beta 92.978(2) _cell_angle_gamma 90 _cell_volume 640.39(5) _symmetry_cell_setting Monoclinic _symmetry_space_group_name_H-M 'P 1 21/n 1 ' _symmetry_space_group_name_Hall ? loop_ _symmetry_equiv_pos_as_xyz 'x, y, z' '-x+1/2, y+1/2, -z+1/2' '-x, -y, -z' 'x-1/2, -y-1/2, z-1/2' _cell_formula_units_Z 4 _chemical_formula_sum 'C7 H6 O4' _chemical_formula_moiety 'C7 H6 O4' _chemical_compound_source ? _chemical_formula_weight 154.12 _cell_measurement_reflns_used 0 _cell_measurement_theta_min 0 _cell_measurement_theta_max 0 _cell_measurement_temperature 200(2) _exptl_crystal_description block _exptl_crystal_colour clear _exptl_crystal_size_min ? _exptl_crystal_size_mid ? _exptl_crystal_size_max ? _exptl_crystal_density_diffrn 1.599 _exptl_crystal_density_method 'not measured' _exptl_crystal_F_000 320 _exptl_absorpt_coefficient_mu 0.134 # Sheldrick geometric approximatio 1.00 1.00 _exptl_absorpt_correction_type none _diffrn_ambient_temperature 200(2) _diffrn_measurement_device_type 'Nonius KappaCCD' _diffrn_measurement_method '\f & \w scans' _diffrn_radiation_monochromator graphite _diffrn_radiation_type 'Mo K\a' _diffrn_radiation_wavelength 0.71073 # If a reference occurs more than once, delete the author # and date from subsequent references. _computing_data_collection 'COLLECT (Nonius, 1997-2001).' _computing_cell_refinement 'DENZO/SCALEPACK (Otwinowski & Minor, 1997)' _computing_data_reduction 'DENZO/SCALEPACK (Otwinowski & Minor, 1997)' _computing_structure_solution 'SIR92 (Altomare et al., 1994)' _computing_structure_refinement 'SHELXL-97 (Sheldrick, 2008)' _computing_molecular_graphics 'ORTEP (Farrugia, 1997), Mercury (McRae, 2006)' _diffrn_reflns_number 12405 _diffrn_reflns_av_R_equivalents 0.0877 _diffrn_reflns_av_unetI/netI 0.0577 _diffrn_reflns_theta_min 1.74 _diffrn_reflns_theta_max 30.15 _diffrn_reflns_theta_full 30.15 _diffrn_measured_fraction_theta_max 0.987 _diffrn_measured_fraction_theta_full 0.987 _diffrn_reflns_limit_h_min -7 _diffrn_reflns_limit_h_max 7 _diffrn_reflns_limit_k_min -6 _diffrn_reflns_limit_k_max 6 _diffrn_reflns_limit_l_min -28 _diffrn_reflns_limit_l_max 32 #============================================================================== # STRUCTURE SOLUTION _atom_sites_solution_primary direct _atom_sites_solution_secondary difmap _atom_sites_solution_hydrogens difmap #============================================================================== # REFINEMENT DATA _refine_special_details ; Refinement of F^2^ against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F^2^, conventional R-factors R are based on F, with F set to zero for negative F^2^. The threshold expression of F^2^ > 2\s(F^2^) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F^2^ are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger. ; _reflns_number_total 1864 _reflns_number_gt 1105 _reflns_threshold_expression >2\s(I) _refine_ls_structure_factor_coef Fsqd _refine_ls_matrix_type full _refine_ls_R_factor_all 0.1107 _refine_ls_R_factor_gt 0.0531 _refine_ls_wR_factor_ref 0.1535 _refine_ls_goodness_of_fit_ref 1.04 _refine_ls_restrained_S_all 1.04 _refine_ls_number_reflns 1864 _refine_ls_number_parameters 124 _refine_ls_number_restraints 0 _refine_ls_hydrogen_treatment refall _refine_ls_weighting_scheme calc _refine_ls_weighting_details 'calc w=1/[\s^2^(Fo^2^)+(0.0597P)^2^+0.4207P] where P=(Fo^2^+2Fc^2^)/3' _refine_ls_shift/su_max 0 _refine_ls_shift/su_mean 0 _refine_diff_density_max 0.267 _refine_diff_density_min -0.265 _refine_diff_density_rms 0.067 _refine_ls_extinction_method none loop_ _atom_type_symbol _atom_type_description _atom_type_scat_dispersion_real _atom_type_scat_dispersion_imag _atom_type_scat_source C C 0.0033 0.0016 'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4' H H 0 0 'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4' O O 0.0106 0.006 'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4' #============================================================================== # ATOMIC COORDINATES AND DISPLACEMENT PARAMETERS loop_ _atom_site_label _atom_site_fract_x _atom_site_fract_y _atom_site_fract_z _atom_site_U_iso_or_equiv _atom_site_adp_type _atom_site_calc_flag _atom_site_refinement_flags _atom_site_occupancy _atom_site_disorder_assembly _atom_site_disorder_group _atom_site_type_symbol C1 0.0854(4) 0.5165(4) 0.10443(8) 0.0221(5) Uani d . 1 . . C C2 0.2877(4) 0.3508(5) 0.10085(9) 0.0251(5) Uani d . 1 . . C O2 0.4415(3) 0.3715(4) 0.05810(7) 0.0376(5) Uani d . 1 . . O C3 0.3372(4) 0.1527(5) 0.14296(9) 0.0273(5) Uani d . 1 . . C C4 0.1908(4) 0.1234(5) 0.18736(9) 0.0255(5) Uani d . 1 . . C C5 -0.0112(4) 0.2896(4) 0.19149(8) 0.0218(5) Uani d . 1 . . C O5 -0.1501(3) 0.2511(3) 0.23800(6) 0.0279(4) Uani d . 1 . . O C6 -0.0655(4) 0.4839(4) 0.15004(8) 0.0220(5) Uani d . 1 . . C C7 0.0328(4) 0.7256(4) 0.06028(8) 0.0247(5) Uani d . 1 . . C O8 0.1657(3) 0.7606(3) 0.02042(6) 0.0345(4) Uani d . 1 . . O O9 -0.1621(3) 0.8712(3) 0.06615(7) 0.0303(4) Uani d . 1 . . O H31 0.486(5) 0.037(5) 0.1395(10) 0.035(7) Uiso d . 1 . . H H41 0.236(4) -0.014(5) 0.2167(10) 0.030(6) Uiso d . 1 . . H H61 -0.209(5) 0.606(6) 0.1521(10) 0.036(7) Uiso d . 1 . . H H1 -0.179(6) 0.987(8) 0.0349(15) 0.077(11) Uiso d . 1 . . H H2 -0.231(6) 0.408(7) 0.2437(13) 0.053(9) Uiso d . 1 . . H H5 0.382(6) 0.517(8) 0.0371(13) 0.060(10) Uiso d . 1 . . H loop_ _atom_site_aniso_label _atom_site_aniso_U_11 _atom_site_aniso_U_22 _atom_site_aniso_U_33 _atom_site_aniso_U_12 _atom_site_aniso_U_13 _atom_site_aniso_U_23 C1 0.0271(11) 0.0213(11) 0.0182(9) -0.0012(9) 0.0033(8) 0.0002(8) C2 0.0259(11) 0.0281(12) 0.0217(10) -0.0014(9) 0.0051(8) -0.0009(9) O2 0.0350(10) 0.0447(11) 0.0349(9) 0.0088(8) 0.0192(7) 0.0103(8) C3 0.0255(11) 0.0279(12) 0.0283(11) 0.0039(9) 0.0014(9) 0.0004(9) C4 0.0305(12) 0.0227(11) 0.0228(10) 0.0003(9) -0.0014(8) 0.0008(9) C5 0.0260(11) 0.0221(11) 0.0175(9) -0.0046(8) 0.0041(8) -0.0011(8) O5 0.0387(10) 0.0249(8) 0.0211(7) 0.0021(7) 0.0108(6) 0.0046(6) C6 0.0257(11) 0.0199(10) 0.0206(10) 0.0007(9) 0.0032(8) -0.0010(8) C7 0.0316(12) 0.0235(11) 0.0192(10) -0.0022(9) 0.0027(8) -0.0012(8) O8 0.0430(10) 0.0362(10) 0.0257(8) 0.0035(8) 0.0141(7) 0.0103(7) O9 0.0345(9) 0.0300(9) 0.0269(8) 0.0058(7) 0.0066(6) 0.0091(7) #============================================================================== # MOLECULAR GEOMETRY _geom_special_details ; All s.u.'s (except the s.u. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell s.u.'s are taken into account individually in the estimation of s.u.'s in distances, angles and torsion angles; correlations between s.u.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell s.u.'s is used for estimating s.u.'s involving l.s. planes. ; loop_ _geom_bond_atom_site_label_1 _geom_bond_atom_site_label_2 _geom_bond_site_symmetry_2 _geom_bond_distance _geom_bond_publ_flag C1 C2 . 1.398(3) ? C1 C6 . 1.406(3) ? C1 C7 . 1.474(3) ? C2 O2 . 1.358(2) ? C2 C3 . 1.400(3) ? O2 H5 . 0.92(4) ? C3 C4 . 1.365(3) ? C3 H31 . 1.01(3) ? C4 C5 . 1.399(3) ? C4 H41 . 0.98(3) ? C5 C6 . 1.382(3) ? C5 O5 . 1.385(2) ? O5 H2 . 0.90(3) ? C6 H61 . 1.00(3) ? C7 O8 . 1.236(2) ? C7 O9 . 1.315(3) ? O9 H1 . 0.93(4) ? loop_ _geom_angle_atom_site_label_1 _geom_angle_atom_site_label_2 _geom_angle_atom_site_label_3 _geom_angle _geom_angle_site_symmetry_1 _geom_angle_site_symmetry_3 _geom_angle_publ_flag C2 C1 C6 119.99(19) . . ? C2 C1 C7 119.51(18) . . ? C6 C1 C7 120.50(19) . . ? O2 C2 C1 123.1(2) . . ? O2 C2 C3 117.6(2) . . ? C1 C2 C3 119.30(19) . . ? C2 O2 H5 103.2(19) . . ? C4 C3 C2 120.4(2) . . ? C4 C3 H31 122.0(14) . . ? C2 C3 H31 117.6(14) . . ? C3 C4 C5 120.7(2) . . ? C3 C4 H41 117.6(14) . . ? C5 C4 H41 121.7(14) . . ? C6 C5 O5 122.41(19) . . ? C6 C5 C4 119.97(19) . . ? O5 C5 C4 117.62(18) . . ? C5 O5 H2 107.8(19) . . ? C5 C6 C1 119.6(2) . . ? C5 C6 H61 121.5(14) . . ? C1 C6 H61 118.8(14) . . ? O8 C7 O9 122.6(2) . . ? O8 C7 C1 121.4(2) . . ? O9 C7 C1 115.98(18) . . ? C7 O9 H1 107(2) . . ? loop_ _geom_torsion_atom_site_label_1 _geom_torsion_atom_site_label_2 _geom_torsion_atom_site_label_3 _geom_torsion_atom_site_label_4 _geom_torsion _geom_torsion_site_symmetry_1 _geom_torsion_site_symmetry_2 _geom_torsion_site_symmetry_3 _geom_torsion_site_symmetry_4 _geom_torsion_publ_flag C6 C1 C2 O2 -179.8(2) . . . . ? C7 C1 C2 O2 -0.1(3) . . . . ? C6 C1 C2 C3 0.2(3) . . . . ? C7 C1 C2 C3 179.9(2) . . . . ? O2 C2 C3 C4 179.4(2) . . . . ? C1 C2 C3 C4 -0.6(3) . . . . ? C2 C3 C4 C5 0.2(3) . . . . ? C3 C4 C5 C6 0.7(3) . . . . ? C3 C4 C5 O5 -179.2(2) . . . . ? O5 C5 C6 C1 178.76(19) . . . . ? C4 C5 C6 C1 -1.1(3) . . . . ? C2 C1 C6 C5 0.7(3) . . . . ? C7 C1 C6 C5 -179.0(2) . . . . ? C2 C1 C7 O8 -1.0(3) . . . . ? C6 C1 C7 O8 178.7(2) . . . . ? C2 C1 C7 O9 179.17(19) . . . . ? C6 C1 C7 O9 -1.1(3) . . . . ? data_25dhoba250kxray _database_code_depnum_ccdc_archive 'CCDC 747940' _chemical_name_systematic '2,5-dihydroxybenzoic acid' _chemical_melting_point ? _cell_length_a 5.6215(6) _cell_length_b 4.8939(6) _cell_length_c 23.492(2) _cell_angle_alpha 90 _cell_angle_beta 92.760(6) _cell_angle_gamma 90 _cell_volume 645.53(12) _symmetry_cell_setting Monoclinic _symmetry_space_group_name_H-M 'P 1 21/n 1 ' _symmetry_space_group_name_Hall ? loop_ _symmetry_equiv_pos_as_xyz 'x, y, z' '-x+1/2, y+1/2, -z+1/2' '-x, -y, -z' 'x-1/2, -y-1/2, z-1/2' _cell_formula_units_Z 4 _chemical_formula_sum 'C7 H6 O4' _chemical_formula_moiety 'C7 H6 O4' _chemical_compound_source ? _chemical_formula_weight 154.12 _cell_measurement_reflns_used 0 _cell_measurement_theta_min 0 _cell_measurement_theta_max 0 _cell_measurement_temperature 250(2) _exptl_crystal_description block _exptl_crystal_colour clear _exptl_crystal_size_min ? _exptl_crystal_size_mid ? _exptl_crystal_size_max ? _exptl_crystal_density_diffrn 1.586 _exptl_crystal_density_method 'not measured' _exptl_crystal_F_000 320 _exptl_absorpt_coefficient_mu 0.133 _exptl_absorpt_correction_type none _diffrn_ambient_temperature 250(2) _diffrn_measurement_device_type 'Nonius Kappa CCD' _diffrn_radiation_monochromator graphite _diffrn_radiation_type 'Mo K\a' _diffrn_radiation_wavelength 0.71073 _diffrn_measurement_method '\f & \w scans' _computing_data_collection 'Nonius (1997-2001). COLLECT.' _computing_data_reduction 'DENZO/SCALEPACK (Otwinowski & Minor, 1997)' _computing_cell_refinement 'DENZO/SCALEPACK (Otwinowski & Minor, 1997)' _computing_structure_solution 'SIR92 (Altomare et al., 1994)' _computing_structure_refinement 'SHELXL-97 (Sheldrick, 2008)' _computing_molecular_graphics 'ORTEP (Farrugia, 1997), Mercury (McRae, 2006)' _diffrn_reflns_number 5664 _diffrn_reflns_av_R_equivalents 0.0917 _diffrn_reflns_av_unetI/netI 0.1097 _diffrn_reflns_theta_min 1.74 _diffrn_reflns_theta_max 30.04 _diffrn_reflns_theta_full 30.04 _diffrn_measured_fraction_theta_max 0.916 _diffrn_measured_fraction_theta_full 0.916 _diffrn_reflns_limit_h_min -7 _diffrn_reflns_limit_h_max 7 _diffrn_reflns_limit_k_min -6 _diffrn_reflns_limit_k_max 6 _diffrn_reflns_limit_l_min -27 _diffrn_reflns_limit_l_max 32 #============================================================================== # STRUCTURE SOLUTION _atom_sites_solution_primary direct _atom_sites_solution_secondary difmap _atom_sites_solution_hydrogens geom #============================================================================== # REFINEMENT DATA _refine_special_details ; Refinement of F^2^ against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F^2^, conventional R-factors R are based on F, with F set to zero for negative F^2^. The threshold expression of F^2^ > 2\s(F^2^) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F^2^ are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger. ; _reflns_number_total 1727 _reflns_number_gt 803 _reflns_threshold_expression >2\s(I) _refine_ls_structure_factor_coef Fsqd _refine_ls_matrix_type full _refine_ls_R_factor_all 0.1685 _refine_ls_R_factor_gt 0.0678 _refine_ls_wR_factor_ref 0.1744 _refine_ls_goodness_of_fit_ref 1.019 _refine_ls_restrained_S_all 1.019 _refine_ls_number_reflns 1727 _refine_ls_number_parameters 125 _refine_ls_number_restraints 0 _refine_ls_hydrogen_treatment refall _refine_ls_weighting_scheme calc _refine_ls_weighting_details 'calc w=1/[\s^2^(Fo^2^)+(0.0511P)^2^+0.6843P] where P=(Fo^2^+2Fc^2^)/3' _refine_ls_shift/su_max 0 _refine_ls_shift/su_mean 0 _refine_diff_density_max 0.285 _refine_diff_density_min -0.264 _refine_diff_density_rms 0.066 _refine_ls_extinction_method SHELXL _refine_ls_extinction_coef 0.019(6) loop_ _atom_type_symbol _atom_type_description _atom_type_scat_dispersion_real _atom_type_scat_dispersion_imag _atom_type_scat_source C C 0.0033 0.0016 'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4' H H 0 0 'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4' O O 0.0106 0.006 'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4' #============================================================================== # ATOMIC COORDINATES AND DISPLACEMENT PARAMETERS loop_ _atom_site_label _atom_site_fract_x _atom_site_fract_y _atom_site_fract_z _atom_site_U_iso_or_equiv _atom_site_adp_type _atom_site_calc_flag _atom_site_refinement_flags _atom_site_occupancy _atom_site_disorder_assembly _atom_site_disorder_group _atom_site_type_symbol C1 0.0853(6) 0.5196(7) 0.10453(12) 0.0256(8) Uani d . 1 . . C C2 0.2861(6) 0.3542(7) 0.10117(13) 0.0302(8) Uani d . 1 . . C O2 0.4404(4) 0.3726(6) 0.05806(11) 0.0476(8) Uani d . 1 . . O C3 0.3366(6) 0.1574(8) 0.14332(15) 0.0344(9) Uani d . 1 . . C C4 0.1898(6) 0.1296(8) 0.18731(13) 0.0310(8) Uani d . 1 . . C C5 -0.0114(5) 0.2946(7) 0.19121(12) 0.0264(8) Uani d . 1 . . C O5 -0.1509(4) 0.2568(5) 0.23805(9) 0.0334(7) Uani d . 1 . . O C6 -0.0646(6) 0.4874(7) 0.15018(13) 0.0255(8) Uani d . 1 . . C C7 0.0326(6) 0.7262(7) 0.06026(13) 0.0297(8) Uani d . 1 . . C O8 0.1655(4) 0.7616(5) 0.02070(10) 0.0423(7) Uani d . 1 . . O O9 -0.1606(4) 0.8729(5) 0.06616(10) 0.0374(7) Uani d . 1 . . O H6 -0.199(6) 0.613(7) 0.1504(13) 0.035(10) Uiso d . 1 . . H H4 0.232(5) -0.017(6) 0.2149(12) 0.022(8) Uiso d . 1 . . H H1 -0.169(8) 1.000(11) 0.034(2) 0.101(18) Uiso d . 1 . . H H3 0.485(7) 0.036(9) 0.1381(16) 0.067(13) Uiso d . 1 . . H H2 0.384(7) 0.525(9) 0.0386(16) 0.052(13) Uiso d . 1 . . H H5 -0.228(8) 0.426(10) 0.2440(19) 0.069(14) Uiso d . 1 . . H loop_ _atom_site_aniso_label _atom_site_aniso_U_11 _atom_site_aniso_U_22 _atom_site_aniso_U_33 _atom_site_aniso_U_12 _atom_site_aniso_U_13 _atom_site_aniso_U_23 C1 0.0316(17) 0.0266(19) 0.0191(15) -0.0019(15) 0.0048(12) -0.0012(13) C2 0.0335(18) 0.031(2) 0.0261(17) -0.0040(16) 0.0048(13) -0.0006(15) O2 0.0457(16) 0.0565(19) 0.0431(16) 0.0121(15) 0.0266(12) 0.0129(15) C3 0.0311(19) 0.035(2) 0.038(2) 0.0044(17) 0.0022(15) 0.0002(17) C4 0.040(2) 0.027(2) 0.0256(17) 0.0005(17) -0.0055(14) 0.0018(15) C5 0.0308(18) 0.0277(19) 0.0209(16) -0.0045(15) 0.0042(13) 0.0006(14) O5 0.0478(15) 0.0291(15) 0.0243(12) -0.0002(12) 0.0118(10) 0.0059(11) C6 0.0326(19) 0.0195(17) 0.0246(16) 0.0025(15) 0.0036(13) -0.0003(13) C7 0.037(2) 0.030(2) 0.0223(16) -0.0005(16) 0.0031(14) 0.0008(14) O8 0.0545(16) 0.0432(17) 0.0308(13) 0.0069(13) 0.0193(11) 0.0120(12) O9 0.0421(14) 0.0370(16) 0.0338(14) 0.0070(13) 0.0079(11) 0.0129(12) #============================================================================== # MOLECULAR GEOMETRY _geom_special_details ; All s.u.'s (except the s.u. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell s.u.'s are taken into account individually in the estimation of s.u.'s in distances, angles and torsion angles; correlations between s.u.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell s.u.'s is used for estimating s.u.'s involving l.s. planes. ; loop_ _geom_bond_atom_site_label_1 _geom_bond_atom_site_label_2 _geom_bond_site_symmetry_2 _geom_bond_distance _geom_bond_publ_flag C1 C2 . 1.394(4) ? C1 C6 . 1.405(4) ? C1 C7 . 1.470(4) ? C2 O2 . 1.368(4) ? C2 C3 . 1.401(5) ? O2 H2 . 0.92(4) ? C3 C4 . 1.360(5) ? C3 H3 . 1.04(4) ? C4 C5 . 1.396(5) ? C4 H4 . 0.99(3) ? C5 C6 . 1.371(4) ? C5 O5 . 1.394(3) ? O5 H5 . 0.95(5) ? C6 H6 . 0.97(3) ? C7 O8 . 1.232(4) ? C7 O9 . 1.315(4) ? O9 H1 . 0.98(5) ? loop_ _geom_angle_atom_site_label_1 _geom_angle_atom_site_label_2 _geom_angle_atom_site_label_3 _geom_angle _geom_angle_site_symmetry_1 _geom_angle_site_symmetry_3 _geom_angle_publ_flag C2 C1 C6 119.7(3) . . ? C2 C1 C7 119.7(3) . . ? C6 C1 C7 120.6(3) . . ? O2 C2 C1 123.2(3) . . ? O2 C2 C3 117.0(3) . . ? C1 C2 C3 119.7(3) . . ? C2 O2 H2 102(2) . . ? C4 C3 C2 119.8(3) . . ? C4 C3 H3 124(2) . . ? C2 C3 H3 117(2) . . ? C3 C4 C5 121.0(3) . . ? C3 C4 H4 115.9(16) . . ? C5 C4 H4 123.1(16) . . ? C6 C5 O5 122.3(3) . . ? C6 C5 C4 120.1(3) . . ? O5 C5 C4 117.6(3) . . ? C5 O5 H5 106(3) . . ? C5 C6 C1 119.7(3) . . ? C5 C6 H6 125.0(19) . . ? C1 C6 H6 115.3(19) . . ? O8 C7 O9 122.4(3) . . ? O8 C7 C1 121.4(3) . . ? O9 C7 C1 116.1(3) . . ? C7 O9 H1 106(3) . . ? loop_ _geom_torsion_atom_site_label_1 _geom_torsion_atom_site_label_2 _geom_torsion_atom_site_label_3 _geom_torsion_atom_site_label_4 _geom_torsion _geom_torsion_site_symmetry_1 _geom_torsion_site_symmetry_2 _geom_torsion_site_symmetry_3 _geom_torsion_site_symmetry_4 _geom_torsion_publ_flag C6 C1 C2 O2 179.9(3) . . . . ? C7 C1 C2 O2 -0.2(5) . . . . ? C6 C1 C2 C3 0.0(5) . . . . ? C7 C1 C2 C3 180.0(3) . . . . ? O2 C2 C3 C4 179.9(3) . . . . ? C1 C2 C3 C4 -0.2(5) . . . . ? C2 C3 C4 C5 0.0(5) . . . . ? C3 C4 C5 C6 0.4(5) . . . . ? C3 C4 C5 O5 -179.0(3) . . . . ? O5 C5 C6 C1 178.8(3) . . . . ? C4 C5 C6 C1 -0.5(5) . . . . ? C2 C1 C6 C5 0.4(5) . . . . ? C7 C1 C6 C5 -179.6(3) . . . . ? C2 C1 C7 O8 -1.7(5) . . . . ? C6 C1 C7 O8 178.2(3) . . . . ? C2 C1 C7 O9 179.6(3) . . . . ? C6 C1 C7 O9 -0.5(5) . . . . ? data_25dhoba300k _database_code_depnum_ccdc_archive 'CCDC 747941' _chemical_name_systematic ; 2,5-dihydroxybenzoic acid ; _chemical_name_common '2,5-dihydroxybenzoic acid' _chemical_melting_point ? _chemical_formula_moiety ? _chemical_formula_sum 'C7 H6 O4' _chemical_formula_weight 154.12 _symmetry_cell_setting monoclinic _symmetry_space_group_name_H-M 'P 1 21/n 1 ' loop_ _symmetry_equiv_pos_as_xyz 'x, y, z' '-x+1/2, y+1/2, -z+1/2' '-x, -y, -z' 'x-1/2, -y-1/2, z-1/2' _cell_length_a 5.6218(4) _cell_length_b 4.9063(3) _cell_length_c 23.5260(13) _cell_angle_alpha 90.00 _cell_angle_beta 92.480(4) _cell_angle_gamma 90.00 _cell_volume 648.29(7) _cell_formula_units_Z 4 _cell_measurement_temperature 300(2) _cell_measurement_reflns_used ? _cell_measurement_theta_min ? _cell_measurement_theta_max ? _exptl_crystal_description block _exptl_crystal_colour clear _exptl_crystal_density_meas ? _exptl_crystal_density_diffrn 1.579 _exptl_crystal_density_method 'not measured' _exptl_crystal_F_000 320 _exptl_absorpt_coefficient_mu 0.132 _exptl_absorpt_correction_type none _exptl_absorpt_process_details ? _exptl_special_details ; ? ; _diffrn_ambient_temperature 300(2) _diffrn_measurement_device_type 'Nonius Kappa CCD' _diffrn_radiation_monochromator graphite _diffrn_radiation_type 'Mo K\a' _diffrn_radiation_wavelength 0.71073 _diffrn_measurement_method '\f & \w scans' _diffrn_reflns_av_R_equivalents 0.1416 _diffrn_reflns_av_unetI/netI 0.0954 _diffrn_reflns_theta_min 1.73 _diffrn_reflns_theta_max 30.08 _diffrn_reflns_theta_full 30.08 _diffrn_measured_fraction_theta_max 0.975 _diffrn_measured_fraction_theta_full 0.975 _diffrn_reflns_limit_h_min -7 _diffrn_reflns_limit_h_max 7 _diffrn_reflns_limit_k_min -6 _diffrn_reflns_limit_k_max 6 _diffrn_reflns_limit_l_min -29 _diffrn_reflns_limit_l_max 32 _computing_data_collection 'Nonius (1997-2001). COLLECT.' _computing_data_reduction 'DENZO/SCALEPACK (Otwinowski & Minor, 1997)' _computing_cell_refinement 'DENZO/SCALEPACK (Otwinowski & Minor, 1997)' _computing_structure_solution 'SIR92 (Altomare et al., 1994)' _computing_structure_refinement 'SHELXL-97 (Sheldrick, 2008)' _computing_molecular_graphics 'ORTEP (Farrugia, 1997), Mercury (McRae, 2006)' #============================================================================== # STRUCTURE SOLUTION _atom_sites_solution_primary direct _atom_sites_solution_secondary difmap _atom_sites_solution_hydrogens geom #============================================================================== # REFINEMENT DATA _refine_special_details ; Refinement of F^2^ against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F^2^, conventional R-factors R are based on F, with F set to zero for negative F^2^. The threshold expression of F^2^ > 2\s(F^2^) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F^2^ are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger. ; _reflns_number_total 1848 _reflns_number_gt 866 _reflns_threshold_expression >2\s(I) _refine_ls_structure_factor_coef Fsqd _refine_ls_matrix_type full _refine_ls_R_factor_all 0.165 _refine_ls_R_factor_gt 0.0712 _refine_ls_wR_factor_ref 0.2148 _refine_ls_goodness_of_fit_ref 1.031 _refine_ls_restrained_S_all 1.031 _refine_ls_number_reflns 1848 _refine_ls_number_parameters 125 _refine_ls_number_restraints 0 _refine_ls_hydrogen_treatment refall _refine_ls_weighting_scheme calc _refine_ls_weighting_details 'calc w=1/[\s^2^(Fo^2^)+(0.0932P)^2^+0.1768P] where P=(Fo^2^+2Fc^2^)/3' _refine_ls_shift/su_max 0 _refine_ls_shift/su_mean 0 _refine_diff_density_max 0.276 _refine_diff_density_min -0.26 _refine_diff_density_rms 0.072 _refine_ls_extinction_method SHELXL _refine_ls_extinction_coef 0.034(11) loop_ _atom_type_symbol _atom_type_description _atom_type_scat_dispersion_real _atom_type_scat_dispersion_imag _atom_type_scat_source C C 0.0033 0.0016 'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4' H H 0 0 'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4' O O 0.0106 0.006 'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4' #============================================================================== # ATOMIC COORDINATES AND DISPLACEMENT PARAMETERS loop_ _atom_site_label _atom_site_fract_x _atom_site_fract_y _atom_site_fract_z _atom_site_U_iso_or_equiv _atom_site_adp_type _atom_site_calc_flag _atom_site_refinement_flags _atom_site_occupancy _atom_site_disorder_assembly _atom_site_disorder_group _atom_site_type_symbol C1 0.0854(5) 0.5222(6) 0.10460(11) 0.0335(7) Uani d . 1 . . C C2 0.2859(6) 0.3579(6) 0.10127(12) 0.0388(8) Uani d . 1 . . C C3 0.3348(6) 0.1628(7) 0.14331(13) 0.0441(8) Uani d . 1 . . C C4 0.1896(6) 0.1355(7) 0.18743(12) 0.0398(8) Uani d . 1 . . C C5 -0.0117(5) 0.2993(6) 0.19148(11) 0.0331(7) Uani d . 1 . . C C6 -0.0648(5) 0.4921(6) 0.15020(12) 0.0342(7) Uani d . 1 . . C C7 0.0346(6) 0.7283(6) 0.06035(12) 0.0380(8) Uani d . 1 . . C O9 -0.1594(4) 0.8740(5) 0.06619(9) 0.0474(7) Uani d . 1 . . O O8 0.1658(4) 0.7622(5) 0.02075(9) 0.0533(7) Uani d . 1 . . O O2 0.4396(4) 0.3753(6) 0.05839(11) 0.0601(8) Uani d . 1 . . O O5 -0.1506(4) 0.2620(5) 0.23792(9) 0.0452(7) Uani d . 1 . . O H3 0.484(8) 0.044(10) 0.1372(17) 0.093(14) Uiso d . 1 . . H H4 0.233(6) -0.006(9) 0.2143(15) 0.061(10) Uiso d . 1 . . H H6 -0.208(6) 0.614(8) 0.1487(14) 0.053(10) Uiso d . 1 . . H H1 -0.163(8) 0.998(12) 0.030(2) 0.122(17) Uiso d . 1 . . H H5 -0.216(6) 0.408(8) 0.2440(15) 0.053(12) Uiso d . 1 . . H H2 0.390(7) 0.506(9) 0.0377(17) 0.065(13) Uiso d . 1 . . H loop_ _atom_site_aniso_label _atom_site_aniso_U_11 _atom_site_aniso_U_22 _atom_site_aniso_U_33 _atom_site_aniso_U_12 _atom_site_aniso_U_13 _atom_site_aniso_U_23 C1 0.0423(17) 0.0318(15) 0.0269(14) -0.0022(13) 0.0066(11) 0.0002(11) C2 0.0441(17) 0.0411(18) 0.0318(15) -0.0016(15) 0.0094(12) -0.0018(13) C3 0.0422(19) 0.0446(19) 0.0454(19) 0.0066(15) 0.0026(14) 0.0015(15) C4 0.0474(19) 0.0377(18) 0.0339(16) 0.0031(15) -0.0034(13) 0.0035(13) C5 0.0393(17) 0.0337(16) 0.0268(14) -0.0060(13) 0.0057(11) -0.0011(12) C6 0.0403(18) 0.0328(16) 0.0297(14) 0.0014(13) 0.0049(12) 0.0014(12) C7 0.048(2) 0.0370(17) 0.0292(15) -0.0039(15) 0.0072(13) 0.0025(12) O9 0.0547(14) 0.0472(14) 0.0412(12) 0.0091(11) 0.0117(10) 0.0137(11) O8 0.0678(17) 0.0545(15) 0.0393(13) 0.0077(12) 0.0225(11) 0.0154(10) O2 0.0577(16) 0.0715(19) 0.0534(16) 0.0129(14) 0.0295(12) 0.0140(14) O5 0.0630(16) 0.0393(14) 0.0346(12) 0.0034(12) 0.0187(10) 0.0074(10) #============================================================================== # MOLECULAR GEOMETRY _geom_special_details ; All s.u.'s (except the s.u. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell s.u.'s are taken into account individually in the estimation of s.u.'s in distances, angles and torsion angles; correlations between s.u.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell s.u.'s is used for estimating s.u.'s involving l.s. planes. ; loop_ _geom_bond_atom_site_label_1 _geom_bond_atom_site_label_2 _geom_bond_site_symmetry_2 _geom_bond_distance _geom_bond_publ_flag C1 C2 . 1.391(4) ? C1 C6 . 1.401(4) ? C1 C7 . 1.470(4) ? C2 O2 . 1.359(4) ? C2 C3 . 1.395(4) ? C3 C4 . 1.355(4) ? C3 H3 . 1.04(5) ? C4 C5 . 1.395(4) ? C4 H4 . 0.96(4) ? C5 C6 . 1.379(4) ? C5 O5 . 1.382(3) ? C6 H6 . 1.00(4) ? C7 O8 . 1.224(3) ? C7 O9 . 1.316(4) ? O9 H1 . 1.05(5) ? O2 H2 . 0.84(4) ? O5 H5 . 0.82(4) ? loop_ _geom_angle_atom_site_label_1 _geom_angle_atom_site_label_2 _geom_angle_atom_site_label_3 _geom_angle _geom_angle_site_symmetry_1 _geom_angle_site_symmetry_3 _geom_angle_publ_flag C2 C1 C6 119.9(3) . . ? C2 C1 C7 119.5(2) . . ? C6 C1 C7 120.6(3) . . ? O2 C2 C1 123.2(3) . . ? O2 C2 C3 117.2(3) . . ? C1 C2 C3 119.6(3) . . ? C4 C3 C2 120.3(3) . . ? C4 C3 H3 125(2) . . ? C2 C3 H3 115(2) . . ? C3 C4 C5 120.9(3) . . ? C3 C4 H4 115.4(19) . . ? C5 C4 H4 123.7(19) . . ? C6 C5 O5 122.3(3) . . ? C6 C5 C4 119.9(3) . . ? O5 C5 C4 117.7(3) . . ? C5 C6 C1 119.5(3) . . ? C5 C6 H6 125.7(19) . . ? C1 C6 H6 114.8(19) . . ? O8 C7 O9 122.3(3) . . ? O8 C7 C1 121.8(3) . . ? O9 C7 C1 115.8(2) . . ? C7 O9 H1 102(3) . . ? C2 O2 H2 106(3) . . ? C5 O5 H5 107(3) . . ? loop_ _geom_torsion_atom_site_label_1 _geom_torsion_atom_site_label_2 _geom_torsion_atom_site_label_3 _geom_torsion_atom_site_label_4 _geom_torsion _geom_torsion_site_symmetry_1 _geom_torsion_site_symmetry_2 _geom_torsion_site_symmetry_3 _geom_torsion_site_symmetry_4 _geom_torsion_publ_flag C6 C1 C2 O2 -180.0(3) . . . . ? C7 C1 C2 O2 -0.6(5) . . . . ? C6 C1 C2 C3 0.4(4) . . . . ? C7 C1 C2 C3 179.8(3) . . . . ? O2 C2 C3 C4 179.6(3) . . . . ? C1 C2 C3 C4 -0.7(5) . . . . ? C2 C3 C4 C5 0.5(5) . . . . ? C3 C4 C5 C6 0.0(5) . . . . ? C3 C4 C5 O5 -179.4(3) . . . . ? O5 C5 C6 C1 179.1(3) . . . . ? C4 C5 C6 C1 -0.3(4) . . . . ? C2 C1 C6 C5 0.1(4) . . . . ? C7 C1 C6 C5 -179.3(3) . . . . ? C2 C1 C7 O8 -0.9(5) . . . . ? C6 C1 C7 O8 178.5(3) . . . . ? C2 C1 C7 O9 179.4(3) . . . . ? C6 C1 C7 O9 -1.2(4) . . . . ? data_25dhoba350k _database_code_depnum_ccdc_archive 'CCDC 747942' _chemical_name_systematic '2,5-dihydroxybenzoic acid' _chemical_melting_point ? _cell_length_a 5.6491(3) _cell_length_b 4.9306(3) _cell_length_c 23.6191(11) _cell_angle_alpha 90 _cell_angle_beta 92.277(3) _cell_angle_gamma 90 _cell_volume 657.35(6) _symmetry_cell_setting Monoclinic _symmetry_space_group_name_H-M 'P 1 21/n 1 ' _symmetry_space_group_name_Hall ? loop_ _symmetry_equiv_pos_as_xyz 'x, y, z' '-x+1/2, y+1/2, -z+1/2' '-x, -y, -z' 'x-1/2, -y-1/2, z-1/2' _cell_formula_units_Z 4 _chemical_formula_sum 'C7 H6 O4' _chemical_formula_moiety 'C7 H6 O4' _chemical_compound_source ? _chemical_formula_weight 154.12 _cell_measurement_reflns_used 0 _cell_measurement_theta_min 0 _cell_measurement_theta_max 0 _cell_measurement_temperature 350(2) _exptl_crystal_description block _exptl_crystal_colour clear _exptl_crystal_size_min ? _exptl_crystal_size_mid ? _exptl_crystal_size_max ? _exptl_crystal_density_diffrn 1.537 _exptl_crystal_density_method 'not measured' _exptl_crystal_F_000 320 _exptl_absorpt_coefficient_mu 0.130 _exptl_absorpt_correction_type none _diffrn_ambient_temperature 350(2) _diffrn_measurement_device_type 'Nonius Kappa CCD' _diffrn_radiation_monochromator graphite _diffrn_radiation_type 'Mo K\a' _diffrn_radiation_wavelength 0.71073 _diffrn_measurement_method '\f & \w scans' _computing_data_collection 'Nonius (1997-2001). COLLECT.' _computing_data_reduction 'DENZO/SCALEPACK (Otwinowski & Minor, 1997)' _computing_cell_refinement 'DENZO/SCALEPACK (Otwinowski & Minor, 1997)' _computing_structure_solution 'SIR92 (Altomare et al., 1994)' _computing_structure_refinement 'SHELXL-97 (Sheldrick, 2008)' _computing_molecular_graphics 'ORTEP (Farrugia, 1997), Mercury (McRae, 2006)' _diffrn_reflns_av_R_equivalents 0.103 _diffrn_reflns_av_unetI/netI 0.0797 _diffrn_reflns_theta_min 1.73 _diffrn_reflns_theta_max 30.08 _diffrn_reflns_theta_full 30.08 _diffrn_measured_fraction_theta_max 0.959 _diffrn_measured_fraction_theta_full 0.959 _diffrn_reflns_limit_h_min -7 _diffrn_reflns_limit_h_max 7 _diffrn_reflns_limit_k_min -6 _diffrn_reflns_limit_k_max 6 _diffrn_reflns_limit_l_min -29 _diffrn_reflns_limit_l_max 32 #============================================================================== # STRUCTURE SOLUTION _atom_sites_solution_primary direct _atom_sites_solution_secondary difmap _atom_sites_solution_hydrogens difmap #============================================================================== # REFINEMENT DATA _refine_special_details ; Refinement of F^2^ against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F^2^, conventional R-factors R are based on F, with F set to zero for negative F^2^. The threshold expression of F^2^ > 2\s(F^2^) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F^2^ are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger. ; _reflns_number_total 1839 _reflns_number_gt 835 _reflns_threshold_expression >2\s(I) _refine_ls_structure_factor_coef Fsqd _refine_ls_matrix_type full _refine_ls_R_factor_all 0.159 _refine_ls_R_factor_gt 0.0626 _refine_ls_wR_factor_ref 0.2239 _refine_ls_goodness_of_fit_ref 1.066 _refine_ls_restrained_S_all 1.066 _refine_ls_number_reflns 1839 _refine_ls_number_parameters 125 _refine_ls_number_restraints 0 _refine_ls_hydrogen_treatment refall _refine_ls_weighting_scheme calc _refine_ls_weighting_details 'calc w=1/[\s^2^(Fo^2^)+(0.0999P)^2^+0.1309P] where P=(Fo^2^+2Fc^2^)/3' _refine_ls_shift/su_max 0 _refine_ls_shift/su_mean 0 _refine_diff_density_max 0.232 _refine_diff_density_min -0.226 _refine_diff_density_rms 0.062 _refine_ls_extinction_method SHELXL _refine_ls_extinction_coef 0.038(13) loop_ _atom_type_symbol _atom_type_description _atom_type_scat_dispersion_real _atom_type_scat_dispersion_imag _atom_type_scat_source C C 0.0033 0.0016 'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4' H H 0 0 'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4' O O 0.0106 0.006 'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4' #============================================================================== # ATOMIC COORDINATES AND DISPLACEMENT PARAMETERS loop_ _atom_site_label _atom_site_fract_x _atom_site_fract_y _atom_site_fract_z _atom_site_U_iso_or_equiv _atom_site_adp_type _atom_site_calc_flag _atom_site_refinement_flags _atom_site_occupancy _atom_site_disorder_assembly _atom_site_disorder_group _atom_site_type_symbol C1 0.0855(5) 0.5250(5) 0.10462(10) 0.0405(7) Uani d . 1 . . C C2 0.2859(6) 0.3617(6) 0.10136(12) 0.0491(8) Uani d . 1 . . C O2 0.4391(4) 0.3787(6) 0.05844(11) 0.0732(8) Uani d . 1 . . O C3 0.3331(6) 0.1676(7) 0.14335(13) 0.0523(9) Uani d . 1 . . C C4 0.1882(6) 0.1414(6) 0.18746(12) 0.0480(8) Uani d . 1 . . C C5 -0.0117(5) 0.3047(6) 0.19164(11) 0.0412(7) Uani d . 1 . . C O5 -0.1508(4) 0.2695(5) 0.23787(8) 0.0551(7) Uani d . 1 . . O C6 -0.0638(5) 0.4954(6) 0.15013(11) 0.0412(7) Uani d . 1 . . C C7 0.0350(6) 0.7304(6) 0.06037(12) 0.0470(8) Uani d . 1 . . C O8 0.1645(4) 0.7631(5) 0.02077(9) 0.0657(8) Uani d . 1 . . O O9 -0.1573(4) 0.8750(5) 0.06639(9) 0.0580(7) Uani d . 1 . . O H3 0.481(7) 0.055(8) 0.1400(14) 0.079(11) Uiso d . 1 . . H H4 0.225(5) -0.002(7) 0.2160(13) 0.060(9) Uiso d . 1 . . H H6 -0.203(6) 0.623(7) 0.1505(12) 0.057(9) Uiso d . 1 . . H H5 -0.219(8) 0.421(9) 0.2441(18) 0.106(16) Uiso d . 1 . . H H1 -0.156(8) 0.997(10) 0.0337(19) 0.113(15) Uiso d . 1 . . H H2 0.377(9) 0.523(10) 0.0375(19) 0.110(16) Uiso d . 1 . . H loop_ _atom_site_aniso_label _atom_site_aniso_U_11 _atom_site_aniso_U_22 _atom_site_aniso_U_33 _atom_site_aniso_U_12 _atom_site_aniso_U_13 _atom_site_aniso_U_23 C1 0.0494(17) 0.0378(15) 0.0347(15) -0.0029(13) 0.0073(12) 0.0000(11) C2 0.0534(19) 0.0500(19) 0.0446(17) -0.0024(15) 0.0096(13) -0.0030(14) O2 0.0661(17) 0.0878(19) 0.0684(17) 0.0145(14) 0.0357(13) 0.0163(15) C3 0.049(2) 0.0546(19) 0.0538(19) 0.0102(16) 0.0036(14) 0.0035(15) C4 0.057(2) 0.0457(18) 0.0411(17) 0.0016(15) -0.0016(13) 0.0044(14) C5 0.0490(18) 0.0395(15) 0.0353(15) -0.0064(13) 0.0052(12) -0.0018(12) O5 0.0761(17) 0.0510(14) 0.0397(12) 0.0041(12) 0.0200(10) 0.0077(10) C6 0.0488(18) 0.0391(16) 0.0361(15) 0.0016(13) 0.0064(12) 0.0013(12) C7 0.061(2) 0.0451(17) 0.0354(15) -0.0027(15) 0.0090(13) 0.0033(13) O8 0.0804(17) 0.0688(16) 0.0497(13) 0.0074(12) 0.0260(12) 0.0183(11) O9 0.0665(15) 0.0582(15) 0.0502(13) 0.0101(12) 0.0119(10) 0.0178(11) #============================================================================== # MOLECULAR GEOMETRY _geom_special_details ; All s.u.'s (except the s.u. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell s.u.'s are taken into account individually in the estimation of s.u.'s in distances, angles and torsion angles; correlations between s.u.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell s.u.'s is used for estimating s.u.'s involving l.s. planes. ; loop_ _geom_bond_atom_site_label_1 _geom_bond_atom_site_label_2 _geom_bond_site_symmetry_2 _geom_bond_distance _geom_bond_publ_flag C1 C2 . 1.394(4) ? C1 C6 . 1.400(4) ? C1 C7 . 1.475(4) ? C2 O2 . 1.362(4) ? C2 C3 . 1.396(4) ? O2 H2 . 0.93(5) ? C3 C4 . 1.356(4) ? C3 H3 . 1.01(4) ? C4 C5 . 1.394(4) ? C4 H4 . 0.99(3) ? C5 O5 . 1.381(3) ? C5 C6 . 1.382(4) ? O5 H5 . 0.86(5) ? C6 H6 . 1.01(3) ? C7 O8 . 1.221(3) ? C7 O9 . 1.312(4) ? O9 H1 . 0.98(5) ? loop_ _geom_angle_atom_site_label_1 _geom_angle_atom_site_label_2 _geom_angle_atom_site_label_3 _geom_angle _geom_angle_site_symmetry_1 _geom_angle_site_symmetry_3 _geom_angle_publ_flag C2 C1 C6 119.8(3) . . ? C2 C1 C7 119.5(3) . . ? C6 C1 C7 120.7(3) . . ? O2 C2 C1 123.2(3) . . ? O2 C2 C3 117.5(3) . . ? C1 C2 C3 119.3(3) . . ? C2 O2 H2 102(3) . . ? C4 C3 C2 120.4(3) . . ? C4 C3 H3 122(2) . . ? C2 C3 H3 117(2) . . ? C3 C4 C5 121.0(3) . . ? C3 C4 H4 118.2(18) . . ? C5 C4 H4 120.8(18) . . ? O5 C5 C6 122.3(3) . . ? O5 C5 C4 118.1(3) . . ? C6 C5 C4 119.6(3) . . ? C5 O5 H5 107(3) . . ? C5 C6 C1 119.9(3) . . ? C5 C6 H6 124.3(17) . . ? C1 C6 H6 115.8(17) . . ? O8 C7 O9 122.4(3) . . ? O8 C7 C1 121.9(3) . . ? O9 C7 C1 115.7(2) . . ? C7 O9 H1 102(3) . . ? loop_ _geom_torsion_atom_site_label_1 _geom_torsion_atom_site_label_2 _geom_torsion_atom_site_label_3 _geom_torsion_atom_site_label_4 _geom_torsion _geom_torsion_site_symmetry_1 _geom_torsion_site_symmetry_2 _geom_torsion_site_symmetry_3 _geom_torsion_site_symmetry_4 _geom_torsion_publ_flag C6 C1 C2 O2 -180.0(3) . . . . ? C7 C1 C2 O2 -0.9(4) . . . . ? C6 C1 C2 C3 0.8(4) . . . . ? C7 C1 C2 C3 180.0(3) . . . . ? O2 C2 C3 C4 179.6(3) . . . . ? C1 C2 C3 C4 -1.2(5) . . . . ? C2 C3 C4 C5 0.7(5) . . . . ? C3 C4 C5 O5 -179.4(3) . . . . ? C3 C4 C5 C6 0.3(4) . . . . ? O5 C5 C6 C1 179.1(3) . . . . ? C4 C5 C6 C1 -0.6(4) . . . . ? C2 C1 C6 C5 0.1(4) . . . . ? C7 C1 C6 C5 -179.0(3) . . . . ? C2 C1 C7 O8 -0.3(4) . . . . ? C6 C1 C7 O8 178.8(3) . . . . ? C2 C1 C7 O9 179.7(3) . . . . ? C6 C1 C7 O9 -1.1(4) . . . . ? data_24DHOBA20K _database_code_depnum_ccdc_archive 'CCDC 747943' _audit_creation_method SHELXL-97 _chemical_name_systematic ; ? ; _chemical_name_common '2,4-Dihydroxybenzoic acid' _chemical_melting_point 498 _chemical_formula_moiety 'C7 H6 O4' _chemical_formula_sum 'C7 H6 O4' _chemical_formula_weight 154.00 _symmetry_cell_setting Monoclinic _symmetry_space_group_name_H-M P21/n _symmetry_space_group_name_Hall -P2yn loop_ _symmetry_equiv_pos_as_xyz 'x, y, z' '-x+1/2, y+1/2, -z+1/2' '-x, -y, -z' 'x-1/2, -y-1/2, z-1/2' _cell_length_a 3.656(2) _cell_length_b 22.329(11) _cell_length_c 8.009(4) _cell_angle_alpha 90.00 _cell_angle_beta 99.76(4) _cell_angle_gamma 90.00 _cell_volume 644.4(6) _cell_formula_units_Z 4 _cell_measurement_temperature 20(2) _cell_measurement_reflns_used 330 _exptl_crystal_description Block _exptl_crystal_colour colourless _exptl_crystal_size_max 3 _exptl_crystal_size_mid 1 _exptl_crystal_size_min 0.5 _exptl_crystal_preparation 'recrystallised from acetone solution' _exptl_crystal_density_diffrn ? _exptl_special_details ; For peak integration a local UB matrix refined for each frame, using approximately 30 reflections from each of the 11 detectors. Hence _cell_measurement_reflns_used 330 For final cell dimensions a weighted average of all local cells was calculated Because of the nature of the experiment, it is not possible to give values of theta_min and theta_max for the cell determination. The same applies for the wavelength used for the experiment. The range of wavelengths used was 0.7-6.9 Angstroms, BUT the bulk of the diffraction information is obtained from wavelengths in the range 0.8-2.9 Angstroms. The data collection procedures on the SXD instrument used for the single crystal neutron data collection are most recently summarised in the Appendix to the following paper Wilson, C.C. (1997). J. Mol. Struct. 405, 207-217. ; _diffrn_ambient_temperature 20(2) _diffrn_radiation_wavelength 0.7-6.9 _diffrn_radiation_probe neutron _diffrn_radiation_type neutron _diffrn_radiation_source 'ISIS spallation source' _diffrn_measurement_device_type 'SXD time-of-flight LAUE diffraction' _diffrn_measurement_method 'time-of-flight LAUE diffraction' _diffrn_reflns_number 8839 _diffrn_reflns_av_R_equivalents 0.0000 _diffrn_reflns_av_sigmaI/netI 0.0633 _diffrn_reflns_limit_h_min -7 _diffrn_reflns_limit_h_max 6 _diffrn_reflns_limit_k_min -57 _diffrn_reflns_limit_k_max 59 _diffrn_reflns_limit_l_min -11 _diffrn_reflns_limit_l_max 21 _reflns_number_total 8839 _reflns_number_gt 8839 _computing_data_collection SXD-2001 _computing_cell_refinement SXD-2001 _computing_data_reduction SXD-2001 _computing_structure_solution 'SHELXL-97 (Sheldrick, 1997)' _computing_structure_refinement 'SHELXL-97 (Sheldrick, 1997)' _computing_molecular_graphics SHELXTL _computing_publication_material SHELXTL _refine_special_details ; The variable wavelength nature of the data collection procedure means that sensible values of _diffrn_reflns_theta_min & _diffrn_reflns_theta_max cannot be given instead the following limits are given _diffrn_reflns_sin(theta)/lambda_min 0.07 _diffrn_reflns_sin(theta)/lambda_max 1.36 _refine_diff_density_max/min is given in Fermi per per angstrom cubed not electons per angstrom cubed. Another way to consider the _refine_diff_density_ is as a percentage of the diffracted intensity of a given atom: _refine_diff_density_max = 6.9% of Carbon _refine_diff_density_min = -4.4% of Carbon Refinement of F^2^ against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F^2^, conventional R-factors R are based on F, with F set to zero for negative F^2^. The threshold expression of F^2^ > 2sigma(F^2^) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F^2^ are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger. ; _refine_ls_hydrogen_treatment refall _refine_ls_number_reflns 8839 _refine_ls_number_parameters 264 _refine_ls_number_restraints 0 _refine_ls_R_factor_all 0.0789 _refine_ls_R_factor_gt 0.0789 _refine_ls_wR_factor_ref 0.2129 _refine_ls_wR_factor_gt 0.2129 _refine_ls_goodness_of_fit_ref 1.048 _refine_ls_shift/su_max 0.001 _refine_ls_shift/su_mean 0.000 loop_ _atom_site_label _atom_site_type_symbol _atom_site_fract_x _atom_site_fract_y _atom_site_fract_z _atom_site_U_iso_or_equiv _atom_site_adp_type _atom_site_occupancy _atom_site_symmetry_multiplicity _atom_site_calc_flag _atom_site_refinement_flags _atom_site_disorder_assembly _atom_site_disorder_group C1 C 0.3030(4) 0.09407(4) 0.71789(9) 0.0056(2) Uani 1 1 d . . . C2 C 0.3971(4) 0.15439(4) 0.75955(9) 0.0063(2) Uani 1 1 d . . . O2 O 0.3842(5) 0.17732(4) 0.91614(11) 0.0083(3) Uani 1 1 d . . . C3 C 0.5044(4) 0.19294(4) 0.63946(10) 0.0065(2) Uani 1 1 d . . . C4 C 0.5205(4) 0.17152(4) 0.47693(9) 0.0064(2) Uani 1 1 d . . . O4 O 0.6210(5) 0.20674(4) 0.35546(12) 0.0085(3) Uani 1 1 d . . . C5 C 0.4265(4) 0.11167(4) 0.43223(9) 0.0071(2) Uani 1 1 d . . . C6 C 0.3203(4) 0.07394(4) 0.55211(9) 0.0065(2) Uani 1 1 d . . . C7 C 0.1812(4) 0.05397(4) 0.84126(10) 0.0058(2) Uani 1 1 d . . . O8 O 0.1526(5) 0.07051(4) 0.98795(11) 0.0085(3) Uani 1 1 d . . . O9 O 0.1025(5) -0.00125(4) 0.78817(12) 0.0088(3) Uani 1 1 d . . . H3 H 0.5761(11) 0.23896(10) 0.6736(3) 0.0226(7) Uani 1 1 d . . . H6 H 0.2448(11) 0.02806(9) 0.5189(3) 0.0233(8) Uani 1 1 d . . . H5 H 0.4433(11) 0.09620(10) 0.3057(2) 0.0224(7) Uani 1 1 d . . . H1 H 0.0150(10) -0.02625(10) 0.8777(3) 0.0201(7) Uani 1 1 d . . . H4 H 0.6993(11) 0.24630(10) 0.3994(3) 0.0214(7) Uani 1 1 d . . . H2 H 0.2989(11) 0.14536(11) 0.9851(3) 0.0230(7) Uani 1 1 d . . . loop_ _atom_site_aniso_label _atom_site_aniso_U_11 _atom_site_aniso_U_22 _atom_site_aniso_U_33 _atom_site_aniso_U_23 _atom_site_aniso_U_13 _atom_site_aniso_U_12 C1 0.0086(7) 0.0042(3) 0.0042(2) 0.00032(17) 0.0017(3) -0.0001(3) C2 0.0105(7) 0.0044(3) 0.0042(2) -0.00008(18) 0.0021(3) -0.0001(3) O2 0.0142(9) 0.0056(3) 0.0053(3) -0.0009(2) 0.0026(4) -0.0006(4) C3 0.0099(7) 0.0047(3) 0.0051(2) 0.00023(18) 0.0016(3) -0.0015(3) C4 0.0091(8) 0.0052(3) 0.0050(2) 0.00076(18) 0.0018(3) -0.0005(3) O4 0.0128(9) 0.0073(3) 0.0058(3) 0.0007(2) 0.0031(4) -0.0021(4) C5 0.0110(8) 0.0054(3) 0.0053(2) -0.00058(18) 0.0027(4) -0.0015(3) C6 0.0097(8) 0.0052(3) 0.0048(2) -0.00045(19) 0.0018(3) -0.0010(3) C7 0.0069(7) 0.0051(3) 0.0053(2) 0.00017(18) 0.0010(3) 0.0000(3) O8 0.0140(9) 0.0063(3) 0.0057(3) 0.0001(2) 0.0030(4) -0.0009(4) O9 0.0149(10) 0.0051(3) 0.0070(3) -0.0007(2) 0.0036(4) -0.0024(4) H3 0.038(2) 0.0134(8) 0.0179(7) -0.0033(6) 0.0078(11) -0.0070(10) H6 0.039(2) 0.0109(7) 0.0221(8) -0.0046(6) 0.0103(12) -0.0047(10) H5 0.037(2) 0.0200(9) 0.0116(6) -0.0050(6) 0.0076(10) -0.0015(10) H1 0.030(2) 0.0145(7) 0.0174(7) 0.0018(6) 0.0073(10) -0.0044(9) H4 0.031(2) 0.0131(7) 0.0219(7) -0.0022(6) 0.0090(11) -0.0080(9) H2 0.036(2) 0.0198(9) 0.0157(7) 0.0035(6) 0.0096(11) -0.0021(10) _geom_special_details ; All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds involving l.s. planes. ; loop_ _geom_bond_atom_site_label_1 _geom_bond_atom_site_label_2 _geom_bond_distance C1 C6 1.4133(12) C1 C2 1.4160(13) C1 C7 1.4579(12) C2 O2 1.3628(12) C2 C3 1.3957(12) O2 H2 0.985(2) C3 C4 1.3974(12) C3 H3 1.084(2) C4 O4 1.3496(13) C4 C5 1.4107(13) O4 H4 0.976(2) C5 C6 1.3816(12) C5 H5 1.0819(19) C6 H6 1.082(2) C7 O8 1.2527(13) C7 O9 1.3200(14) O9 H1 1.003(2) loop_ _geom_angle_atom_site_label_1 _geom_angle_atom_site_label_2 _geom_angle_atom_site_label_3 _geom_angle C6 C1 C2 118.43(7) C6 C1 C7 120.59(8) C2 C1 C7 120.96(7) O2 C2 C3 117.40(9) O2 C2 C1 121.95(8) C3 C2 C1 120.65(7) C2 O2 H2 107.90(16) C2 C3 C4 119.47(8) C2 C3 H3 119.66(12) C4 C3 H3 120.87(13) O4 C4 C3 122.11(9) O4 C4 C5 116.97(8) C3 C4 C5 120.92(7) C4 O4 H4 111.52(14) C6 C5 C4 119.10(7) C6 C5 H5 121.56(15) C4 C5 H5 119.34(15) C5 C6 C1 121.44(8) C5 C6 H6 119.77(13) C1 C6 H6 118.78(13) O8 C7 O9 121.95(9) O8 C7 C1 122.56(9) O9 C7 C1 115.49(8) C7 O9 H1 111.61(15) loop_ _geom_hbond_atom_site_label_D _geom_hbond_atom_site_label_H _geom_hbond_atom_site_label_A _geom_hbond_distance_DH _geom_hbond_distance_HA _geom_hbond_distance_DA _geom_hbond_angle_DHA _geom_hbond_site_symmetry_A O9 H1 O8 1.003(2) 1.653(2) 2.6539(17) 175.1(3) 3_557 O4 H4 O2 0.976(2) 1.831(3) 2.776(2) 162.13(19) 4_665 O2 H2 O8 0.985(2) 1.756(3) 2.6270(19) 145.40(19) . _refine_diff_density_max 0.496 _refine_diff_density_min -0.322 _refine_diff_density_rms 0.066 data_24dhoba90k _database_code_depnum_ccdc_archive 'CCDC 747944' _audit_creation_method SHELXL-97 _chemical_name_systematic ; ? ; _chemical_name_common '2,4-Dihydroxybenzoic acid' _chemical_melting_point 498 _chemical_formula_moiety 'C7 H6 O4' _chemical_formula_sum 'C7 H6 O4' _chemical_formula_weight 154.00 _symmetry_cell_setting Monoclinic _symmetry_space_group_name_H-M P21/n _symmetry_space_group_name_Hall -P2yn loop_ _symmetry_equiv_pos_as_xyz 'x, y, z' '-x+1/2, y+1/2, -z+1/2' '-x, -y, -z' 'x-1/2, -y-1/2, z-1/2' _cell_length_a 3.669(2) _cell_length_b 22.3473(12) _cell_length_c 8.012(4) _cell_angle_alpha 90.00 _cell_angle_beta 99.63(4) _cell_angle_gamma 90.00 _cell_volume 647.7(5) _cell_formula_units_Z 4 _cell_measurement_temperature 90(2) _cell_measurement_reflns_used 330 _exptl_crystal_description Block _exptl_crystal_colour colourless _exptl_crystal_size_max 3 _exptl_crystal_size_mid 1 _exptl_crystal_size_min 0.5 _exptl_crystal_preparation 'recrystallised from acetone solution' _exptl_crystal_density_diffrn ? _exptl_special_details ; For peak integration a local UB matrix refined for each frame, using approximately 30 reflections from each of the 11 detectors. Hence _cell_measurement_reflns_used 330 For final cell dimensions a weighted average of all local cells was calculated Because of the nature of the experiment, it is not possible to give values of theta_min and theta_max for the cell determination. The same applies for the wavelength used for the experiment. The range of wavelengths used was 0.7-6.9 Angstroms, BUT the bulk of the diffraction information is obtained from wavelengths in the range 0.8-2.9 Angstroms. The data collection procedures on the SXD instrument used for the single crystal neutron data collection are most recently summarised in the Appendix to the following paper Wilson, C.C. (1997). J. Mol. Struct. 405, 207-217. ; _diffrn_ambient_temperature 90(2) _diffrn_radiation_wavelength 0.7-6.9 _diffrn_radiation_probe neutron _diffrn_radiation_type neutron _diffrn_radiation_source 'ISIS spallation source' _diffrn_measurement_device_type 'SXD time-of-flight LAUE diffraction' _diffrn_measurement_method 'time-of-flight LAUE diffraction' _diffrn_reflns_number 5840 _diffrn_reflns_av_R_equivalents 0.0000 _diffrn_reflns_av_sigmaI/netI 0.0693 _diffrn_reflns_limit_h_min -7 _diffrn_reflns_limit_h_max 5 _diffrn_reflns_limit_k_min -54 _diffrn_reflns_limit_k_max 52 _diffrn_reflns_limit_l_min -11 _diffrn_reflns_limit_l_max 20 _reflns_number_total 5840 _reflns_number_gt 5840 _computing_data_collection SXD-2001 _computing_cell_refinement SXD-2001 _computing_data_reduction SXD-2001 _computing_structure_solution 'SHELXL-97 (Sheldrick, 1997)' _computing_structure_refinement 'SHELXL-97 (Sheldrick, 1997)' _computing_molecular_graphics SHELXTL _computing_publication_material SHELXTL _refine_special_details ; The variable wavelength nature of the data collection procedure means that sensible values of _diffrn_reflns_theta_min & _diffrn_reflns_theta_max cannot be given instead the following limits are given _diffrn_reflns_sin(theta)/lambda_min 0.07 _diffrn_reflns_sin(theta)/lambda_max 1.35 _refine_diff_density_max/min is given in Fermi per per angstrom cubed not electons per angstrom cubed. Another way to consider the _refine_diff_density_ is as a percentage of the diffracted intensity of a given atom: _refine_diff_density_max = 6.61% of Carbon _refine_diff_density_min = -4.21% of Carbon Refinement of F^2^ against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F^2^, conventional R-factors R are based on F, with F set to zero for negative F^2^. The threshold expression of F^2^ > 2sigma(F^2^) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F^2^ are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger. ; _refine_ls_hydrogen_treatment refall _refine_ls_number_reflns 5840 _refine_ls_number_parameters 242 _refine_ls_number_restraints 0 _refine_ls_R_factor_all 0.0813 _refine_ls_R_factor_gt 0.0813 _refine_ls_wR_factor_ref 0.2226 _refine_ls_wR_factor_gt 0.2226 _refine_ls_goodness_of_fit_ref 1.013 _refine_ls_shift/su_max 0.001 _refine_ls_shift/su_mean 0.000 loop_ _atom_site_label _atom_site_type_symbol _atom_site_fract_x _atom_site_fract_y _atom_site_fract_z _atom_site_U_iso_or_equiv _atom_site_adp_type _atom_site_occupancy _atom_site_symmetry_multiplicity _atom_site_calc_flag _atom_site_refinement_flags _atom_site_disorder_assembly _atom_site_disorder_group C1 C 0.3019(5) 0.09408(5) 0.71768(14) 0.0091(3) Uani 1 1 d . . . C2 C 0.3944(5) 0.15419(5) 0.75948(13) 0.0102(3) Uani 1 1 d . . . O2 O 0.3793(6) 0.17734(6) 0.91564(16) 0.0140(4) Uani 1 1 d . . . C3 C 0.5004(5) 0.19288(5) 0.63944(14) 0.0108(3) Uani 1 1 d . . . C4 C 0.5174(5) 0.17151(5) 0.47721(14) 0.0104(3) Uani 1 1 d . . . O4 O 0.6180(6) 0.20674(6) 0.35550(17) 0.0139(4) Uani 1 1 d . . . C5 C 0.4250(5) 0.11169(5) 0.43261(14) 0.0118(3) Uani 1 1 d . . . C6 C 0.3190(5) 0.07396(5) 0.55232(14) 0.0100(3) Uani 1 1 d . . . C7 C 0.1806(5) 0.05405(5) 0.84121(14) 0.0106(3) Uani 1 1 d . . . O8 O 0.1500(6) 0.07045(6) 0.98739(16) 0.0144(4) Uani 1 1 d . . . O9 O 0.1029(6) -0.00124(7) 0.78842(17) 0.0148(4) Uani 1 1 d . . . H3 H 0.5710(14) 0.23894(14) 0.6737(3) 0.0285(9) Uani 1 1 d . . . H6 H 0.2473(13) 0.02806(13) 0.5189(4) 0.0269(9) Uani 1 1 d . . . H4 H 0.6940(14) 0.24625(13) 0.3989(4) 0.0270(8) Uani 1 1 d . . . H1 H 0.0169(13) -0.02596(13) 0.8777(4) 0.0260(9) Uani 1 1 d . . . H5 H 0.4429(14) 0.09653(15) 0.3060(3) 0.0299(10) Uani 1 1 d . . . H2 H 0.2949(14) 0.14554(15) 0.9841(3) 0.0303(10) Uani 1 1 d . . . loop_ _atom_site_aniso_label _atom_site_aniso_U_11 _atom_site_aniso_U_22 _atom_site_aniso_U_33 _atom_site_aniso_U_23 _atom_site_aniso_U_13 _atom_site_aniso_U_12 C1 0.0111(9) 0.0075(4) 0.0087(4) -0.0002(3) 0.0014(5) -0.0017(4) C2 0.0152(10) 0.0069(4) 0.0087(4) -0.0001(3) 0.0031(5) 0.0003(4) O2 0.0245(13) 0.0087(5) 0.0098(4) -0.0004(4) 0.0057(6) 0.0000(6) C3 0.0164(10) 0.0068(4) 0.0096(4) 0.0006(3) 0.0036(5) -0.0009(4) C4 0.0140(10) 0.0083(5) 0.0088(4) 0.0012(3) 0.0020(5) -0.0003(4) O4 0.0211(13) 0.0116(6) 0.0103(5) 0.0023(4) 0.0058(6) -0.0026(6) C5 0.0162(10) 0.0100(5) 0.0101(4) -0.0011(3) 0.0045(5) -0.0016(5) C6 0.0136(10) 0.0079(4) 0.0092(4) -0.0007(3) 0.0037(5) -0.0007(4) C7 0.0146(10) 0.0080(4) 0.0093(4) 0.0004(3) 0.0027(5) -0.0013(4) O8 0.0254(13) 0.0094(5) 0.0094(4) 0.0001(4) 0.0059(6) -0.0023(6) O9 0.0233(13) 0.0089(5) 0.0131(5) -0.0001(4) 0.0058(7) -0.0036(6) H3 0.048(3) 0.0155(11) 0.0235(11) -0.0042(8) 0.0096(15) -0.0095(13) H6 0.041(3) 0.0158(11) 0.0244(11) -0.0051(9) 0.0054(16) -0.0074(14) H4 0.040(3) 0.0162(11) 0.0274(11) 0.0008(9) 0.0123(15) -0.0045(13) H1 0.040(3) 0.0166(11) 0.0233(11) 0.0034(9) 0.0103(15) -0.0046(13) H5 0.048(3) 0.0283(14) 0.0145(9) -0.0039(9) 0.0100(14) -0.0048(16) H2 0.051(3) 0.0240(13) 0.0183(10) 0.0019(9) 0.0130(16) -0.0054(15) _geom_special_details ; All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds involving l.s. planes. ; loop_ _geom_bond_atom_site_label_1 _geom_bond_atom_site_label_2 _geom_bond_distance C1 C6 1.4104(16) C1 C2 1.4121(17) C1 C7 1.4579(16) C2 O2 1.3635(17) C2 C3 1.3961(16) O2 H2 0.979(3) C3 C4 1.3960(16) C3 H3 1.085(3) C4 O4 1.3517(17) C4 C5 1.4105(17) O4 H4 0.973(3) C5 C6 1.3810(16) C5 H5 1.082(3) C6 H6 1.081(3) C7 O8 1.2501(17) C7 O9 1.3214(19) O9 H1 0.996(3) loop_ _geom_angle_atom_site_label_1 _geom_angle_atom_site_label_2 _geom_angle_atom_site_label_3 _geom_angle C6 C1 C2 118.65(10) C6 C1 C7 120.58(11) C2 C1 C7 120.75(10) O2 C2 C3 117.13(12) O2 C2 C1 122.24(11) C3 C2 C1 120.62(10) C2 O2 H2 107.7(2) C2 C3 C4 119.38(11) C2 C3 H3 119.69(17) C4 C3 H3 120.92(17) O4 C4 C3 122.18(12) O4 C4 C5 116.90(11) C3 C4 C5 120.92(10) C4 O4 H4 111.54(19) C6 C5 C4 119.11(10) C6 C5 H5 121.9(2) C4 C5 H5 119.0(2) C5 C6 C1 121.31(11) C5 C6 H6 119.51(18) C1 C6 H6 119.18(18) O8 C7 O9 121.72(12) O8 C7 C1 122.79(13) O9 C7 C1 115.49(11) C7 O9 H1 111.5(2) loop_ _geom_hbond_atom_site_label_D _geom_hbond_atom_site_label_H _geom_hbond_atom_site_label_A _geom_hbond_distance_DH _geom_hbond_distance_HA _geom_hbond_distance_DA _geom_hbond_angle_DHA _geom_hbond_site_symmetry_A O9 H1 O8 0.996(3) 1.659(3) 2.653(2) 174.9(4) 3_557 O4 H4 O2 0.973(3) 1.835(3) 2.776(2) 162.1(3) 4_665 O2 H2 O8 0.979(3) 1.762(4) 2.628(2) 145.5(3) . _refine_diff_density_max 0.333 _refine_diff_density_min -0.211 _refine_diff_density_rms 0.053 data_24dhoba150k _database_code_depnum_ccdc_archive 'CCDC 747945' _audit_creation_method SHELXL-97 _chemical_name_systematic ; ? ; _chemical_name_common '2,4-Dihydroxybenzoic acid' _chemical_melting_point 498 _chemical_formula_moiety 'C7 H6 O4' _chemical_formula_sum 'C7 H6 O4' _chemical_formula_weight 154.00 _symmetry_cell_setting Monoclinic _symmetry_space_group_name_H-M P21/n _symmetry_space_group_name_Hall -P2yn loop_ _symmetry_equiv_pos_as_xyz 'x, y, z' '-x+1/2, y+1/2, -z+1/2' '-x, -y, -z' 'x-1/2, -y-1/2, z-1/2' _cell_length_a 3.686(2) _cell_length_b 22.368(13) _cell_length_c 8.015(4) _cell_angle_alpha 90.00 _cell_angle_beta 99.44(4) _cell_angle_gamma 90.00 _cell_volume 651.9(7) _cell_formula_units_Z 4 _cell_measurement_temperature 150(2) _cell_measurement_reflns_used 330 _exptl_crystal_description Block _exptl_crystal_colour colourless _exptl_crystal_size_max 3 _exptl_crystal_size_mid 1 _exptl_crystal_size_min 0.5 _exptl_crystal_preparation 'recrystallised from acetone solution' _exptl_crystal_density_diffrn ? _exptl_special_details ; For peak integration a local UB matrix refined for each frame, using approximately 30 reflections from each of the 11 detectors. Hence _cell_measurement_reflns_used 330 For final cell dimensions a weighted average of all local cells was calculated Because of the nature of the experiment, it is not possible to give values of theta_min and theta_max for the cell determination. The same applies for the wavelength used for the experiment. The range of wavelengths used was 0.7-6.9 Angstroms, BUT the bulk of the diffraction information is obtained from wavelengths in the range 0.8-2.9 Angstroms. The data collection procedures on the SXD instrument used for the single crystal neutron data collection are most recently summarised in the Appendix to the following paper Wilson, C.C. (1997). J. Mol. Struct. 405, 207-217. ; _diffrn_ambient_temperature 150(2) _diffrn_radiation_wavelength 0.7-6.9 _diffrn_radiation_probe neutron _diffrn_radiation_type neutron _diffrn_radiation_source 'ISIS spallation source' _diffrn_measurement_device_type 'SXD time-of-flight LAUE diffraction' _diffrn_measurement_method 'time-of-flight LAUE diffraction' _diffrn_reflns_number 4920 _diffrn_reflns_av_R_equivalents 0.0000 _diffrn_reflns_av_sigmaI/netI 0.0727 _diffrn_reflns_limit_h_min -5 _diffrn_reflns_limit_h_max 7 _diffrn_reflns_limit_k_min -44 _diffrn_reflns_limit_k_max 47 _diffrn_reflns_limit_l_min -18 _diffrn_reflns_limit_l_max 18 _reflns_number_total 4920 _reflns_number_gt 4920 _computing_data_collection SXD-2001 _computing_cell_refinement SXD-2001 _computing_data_reduction SXD-2001 _computing_structure_solution 'SHELXL-97 (Sheldrick, 1997)' _computing_structure_refinement 'SHELXL-97 (Sheldrick, 1997)' _computing_molecular_graphics SHELXTL _computing_publication_material SHELXTL _refine_special_details ; The variable wavelength nature of the data collection procedure means that sensible values of _diffrn_reflns_theta_min & _diffrn_reflns_theta_max cannot be given instead the following limits are given _diffrn_reflns_sin(theta)/lambda_min 0.07 _diffrn_reflns_sin(theta)/lambda_max 1.10 _refine_diff_density_max/min is given in Fermi per per angstrom cubed not electons per angstrom cubed. Another way to consider the _refine_diff_density_ is as a percentage of the diffracted intensity of a given atom: _refine_diff_density_max = 5.41% of Carbon _refine_diff_density_min = -3.70% of Carbon Refinement of F^2^ against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F^2^, conventional R-factors R are based on F, with F set to zero for negative F^2^. The threshold expression of F^2^ > 2sigma(F^2^) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F^2^ are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger. ; _refine_ls_hydrogen_treatment refall _refine_ls_number_reflns 4920 _refine_ls_number_parameters 242 _refine_ls_number_restraints 0 _refine_ls_R_factor_all 0.0744 _refine_ls_R_factor_gt 0.0744 _refine_ls_wR_factor_ref 0.1931 _refine_ls_wR_factor_gt 0.1931 _refine_ls_goodness_of_fit_ref 1.047 _refine_ls_shift/su_max 0.001 _refine_ls_shift/su_mean 0.000 loop_ _atom_site_label _atom_site_type_symbol _atom_site_fract_x _atom_site_fract_y _atom_site_fract_z _atom_site_U_iso_or_equiv _atom_site_adp_type _atom_site_occupancy _atom_site_symmetry_multiplicity _atom_site_calc_flag _atom_site_refinement_flags _atom_site_disorder_assembly _atom_site_disorder_group C1 C 0.3001(5) 0.09409(6) 0.71787(16) 0.0137(3) Uani 1 1 d . . . C2 C 0.3895(6) 0.15431(6) 0.75890(16) 0.0148(3) Uani 1 1 d . . . O2 O 0.3750(7) 0.17716(8) 0.9149(2) 0.0203(5) Uani 1 1 d . . . C3 C 0.4968(6) 0.19281(6) 0.63915(17) 0.0158(3) Uani 1 1 d . . . C4 C 0.5143(6) 0.17154(6) 0.47716(17) 0.0148(3) Uani 1 1 d . . . O4 O 0.6145(7) 0.20663(8) 0.3559(2) 0.0213(5) Uani 1 1 d . . . C5 C 0.4235(6) 0.11189(6) 0.43244(17) 0.0163(3) Uani 1 1 d . . . C6 C 0.3181(5) 0.07402(6) 0.55234(16) 0.0152(3) Uani 1 1 d . . . C7 C 0.1786(6) 0.05408(6) 0.84096(17) 0.0151(3) Uani 1 1 d . . . O8 O 0.1477(7) 0.07041(8) 0.9872(2) 0.0210(5) Uani 1 1 d . . . O9 O 0.1043(8) -0.00112(8) 0.7886(2) 0.0218(5) Uani 1 1 d . . . H3 H 0.5649(15) 0.23873(15) 0.6723(4) 0.0362(11) Uani 1 1 d . . . H5 H 0.4465(15) 0.09596(17) 0.3076(4) 0.0362(11) Uani 1 1 d . . . H6 H 0.2449(14) 0.02839(15) 0.5192(4) 0.0350(10) Uani 1 1 d . . . H1 H 0.0153(14) -0.02574(15) 0.8777(4) 0.0321(10) Uani 1 1 d . . . H4 H 0.6894(14) 0.24646(15) 0.3991(4) 0.0330(10) Uani 1 1 d . . . H2 H 0.2880(15) 0.14564(16) 0.9830(4) 0.0370(11) Uani 1 1 d . . . loop_ _atom_site_aniso_label _atom_site_aniso_U_11 _atom_site_aniso_U_22 _atom_site_aniso_U_33 _atom_site_aniso_U_23 _atom_site_aniso_U_13 _atom_site_aniso_U_12 C1 0.0163(11) 0.0111(5) 0.0140(5) 0.0001(4) 0.0035(6) -0.0005(5) C2 0.0215(11) 0.0098(5) 0.0136(5) -0.0001(4) 0.0045(6) -0.0006(6) O2 0.0337(15) 0.0131(6) 0.0152(6) -0.0016(5) 0.0076(8) -0.0014(7) C3 0.0226(11) 0.0100(5) 0.0160(5) 0.0010(4) 0.0068(6) -0.0008(5) C4 0.0190(11) 0.0123(6) 0.0137(5) 0.0019(4) 0.0044(6) -0.0010(5) O4 0.0316(15) 0.0168(8) 0.0172(6) 0.0032(5) 0.0093(8) -0.0021(8) C5 0.0210(11) 0.0142(6) 0.0146(5) -0.0008(4) 0.0054(6) -0.0022(6) C6 0.0196(11) 0.0123(5) 0.0143(5) -0.0007(4) 0.0047(6) -0.0013(6) C7 0.0188(11) 0.0123(6) 0.0142(5) 0.0012(4) 0.0025(6) -0.0005(6) O8 0.0350(15) 0.0141(7) 0.0147(6) 0.0006(5) 0.0068(8) -0.0047(8) O9 0.0363(16) 0.0131(7) 0.0176(7) -0.0007(5) 0.0091(9) -0.0055(8) H3 0.058(4) 0.0183(14) 0.0349(15) -0.0039(11) 0.014(2) -0.0082(16) H5 0.054(4) 0.0360(18) 0.0204(12) -0.0058(11) 0.0123(17) -0.0050(19) H6 0.054(3) 0.0225(14) 0.0304(14) -0.0057(11) 0.0140(18) -0.0076(17) H1 0.047(3) 0.0227(14) 0.0277(13) 0.0061(10) 0.0107(17) -0.0046(16) H4 0.046(3) 0.0224(14) 0.0325(14) 0.0003(11) 0.0128(18) -0.0053(16) H2 0.064(4) 0.0259(15) 0.0241(13) 0.0024(11) 0.0155(18) -0.0085(18) _geom_special_details ; All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds involving l.s. planes. ; loop_ _geom_bond_atom_site_label_1 _geom_bond_atom_site_label_2 _geom_bond_distance C1 C6 1.4125(19) C1 C2 1.413(2) C1 C7 1.456(2) C2 O2 1.360(2) C2 C3 1.3943(19) O2 H2 0.977(4) C3 C4 1.394(2) C3 H3 1.080(4) C4 O4 1.348(2) C4 C5 1.408(2) O4 H4 0.979(4) C5 C6 1.384(2) C5 H5 1.079(3) C6 H6 1.078(4) C7 O8 1.251(2) C7 O9 1.318(2) O9 H1 0.999(4) loop_ _geom_angle_atom_site_label_1 _geom_angle_atom_site_label_2 _geom_angle_atom_site_label_3 _geom_angle C6 C1 C2 118.46(12) C6 C1 C7 120.55(13) C2 C1 C7 120.95(12) O2 C2 C3 117.33(14) O2 C2 C1 121.97(13) C3 C2 C1 120.70(12) C2 O2 H2 108.0(3) C4 C3 C2 119.46(13) C4 C3 H3 120.6(2) C2 C3 H3 119.9(2) O4 C4 C3 122.21(15) O4 C4 C5 116.77(13) C3 C4 C5 121.02(12) C4 O4 H4 111.7(2) C6 C5 C4 119.04(12) C6 C5 H5 121.1(2) C4 C5 H5 119.9(2) C5 C6 C1 121.31(14) C5 C6 H6 119.7(2) C1 C6 H6 118.9(2) O8 C7 O9 121.74(15) O8 C7 C1 122.74(15) O9 C7 C1 115.51(13) C7 O9 H1 111.3(3) loop_ _geom_hbond_atom_site_label_D _geom_hbond_atom_site_label_H _geom_hbond_atom_site_label_A _geom_hbond_distance_DH _geom_hbond_distance_HA _geom_hbond_distance_DA _geom_hbond_angle_DHA _geom_hbond_site_symmetry_A O9 H1 O8 0.999(4) 1.657(4) 2.654(3) 175.2(4) 3_557 O4 H4 O2 0.979(4) 1.837(4) 2.785(3) 161.9(3) 4_665 O2 H2 O8 0.977(4) 1.762(4) 2.626(3) 145.4(3) . _refine_diff_density_max 0.187 _refine_diff_density_min -0.135 _refine_diff_density_rms 0.035 data_25dhoba20k _database_code_depnum_ccdc_archive 'CCDC 747946' _audit_creation_method SHELXL-97 _chemical_name_systematic ; ? ; _chemical_name_common '2,5-Dihydroxybenzoic acid' _chemical_melting_point 477 _chemical_formula_moiety 'C7 H6 O4' _chemical_formula_sum 'C7 H6 O4' _chemical_formula_weight 154.00 _symmetry_cell_setting Monoclinic _symmetry_space_group_name_H-M P21/n _symmetry_space_group_name_Hall -P2yn loop_ _symmetry_equiv_pos_as_xyz 'x, y, z' '-x+1/2, y+1/2, -z+1/2' '-x, -y, -z' 'x-1/2, -y-1/2, z-1/2' _cell_length_a 5.545(3) _cell_length_b 4.877(3) _cell_length_c 23.3506(11) _cell_angle_alpha 90.00 _cell_angle_beta 93.62(3) _cell_angle_gamma 90.00 _cell_volume 630.1(5) _cell_formula_units_Z 4 _cell_measurement_temperature 20(2) _cell_measurement_reflns_used 330 _exptl_crystal_description Block _exptl_crystal_colour colourless _exptl_crystal_size_max 7 _exptl_crystal_size_mid 3 _exptl_crystal_size_min 1 _exptl_crystal_preparation 'recrystallised from acetone solution' _exptl_crystal_density_diffrn ? _exptl_special_details ; For peak integration a local UB matrix refined for each frame, using approximately 30 reflections from each of the 11 detectors. Hence _cell_measurement_reflns_used 330 For final cell dimensions a weighted average of all local cells was calculated Because of the nature of the experiment, it is not possible to give values of theta_min and theta_max for the cell determination. The same applies for the wavelength used for the experiment. The range of wavelengths used was 0.7-6.9 Angstroms, BUT the bulk of the diffraction information is obtained from wavelengths in the range 0.8-2.9 Angstroms. The data collection procedures on the SXD instrument used for the single crystal neutron data collection are most recently summarised in the Appendix to the following paper Wilson, C.C. (1997). J. Mol. Struct. 405, 207-217. ; _diffrn_ambient_temperature 20(2) _diffrn_radiation_wavelength 0.7-6.9 _diffrn_radiation_probe neutron _diffrn_radiation_type neutron _diffrn_radiation_source 'ISIS spallation source' _diffrn_measurement_device_type 'SXD time-of-flight LAUE diffraction' _diffrn_measurement_method 'time-of-flight LAUE diffraction' _diffrn_reflns_number 8671 _diffrn_reflns_av_R_equivalents 0.0000 _diffrn_reflns_av_sigmaI/netI 0.0324 _diffrn_reflns_limit_h_min -15 _diffrn_reflns_limit_h_max 15 _diffrn_reflns_limit_k_min -8 _diffrn_reflns_limit_k_max 10 _diffrn_reflns_limit_l_min -38 _diffrn_reflns_limit_l_max 60 _reflns_number_total 8671 _reflns_number_gt 8671 _computing_data_collection SXD-2001 _computing_cell_refinement SXD-2001 _computing_data_reduction SXD-2001 _computing_structure_solution 'SHELXL-97 (Sheldrick, 1997)' _computing_structure_refinement 'SHELXL-97 (Sheldrick, 1997)' _computing_molecular_graphics SHELXTL _computing_publication_material SHELXTL _refine_special_details ; The variable wavelength nature of the data collection procedure means that sensible values of _diffrn_reflns_theta_min & _diffrn_reflns_theta_max cannot be given instead the following limits are given _diffrn_reflns_sin(theta)/lambda_min 0.09 _diffrn_reflns_sin(theta)/lambda_max 1.30 _refine_diff_density_max/min is given in Fermi per per angstrom cubed not electons per angstrom cubed. Another way to consider the _refine_diff_density_ is as a percentage of the diffracted intensity of a given atom: _refine_diff_density_max = 7.49% of Carbon _refine_diff_density_min = -4.32% of Carbon Refinement of F^2^ against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F^2^, conventional R-factors R are based on F, with F set to zero for negative F^2^. The threshold expression of F^2^ > 2sigma(F^2^) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F^2^ are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger. ; _refine_ls_hydrogen_treatment refall _refine_ls_number_reflns 8671 _refine_ls_number_parameters 263 _refine_ls_number_restraints 0 _refine_ls_R_factor_all 0.0927 _refine_ls_R_factor_gt 0.0927 _refine_ls_wR_factor_ref 0.2903 _refine_ls_wR_factor_gt 0.2903 _refine_ls_goodness_of_fit_ref 1.429 _refine_ls_shift/su_max 0.001 _refine_ls_shift/su_mean 0.000 loop_ _atom_site_label _atom_site_type_symbol _atom_site_fract_x _atom_site_fract_y _atom_site_fract_z _atom_site_U_iso_or_equiv _atom_site_adp_type _atom_site_occupancy _atom_site_symmetry_multiplicity _atom_site_calc_flag _atom_site_refinement_flags _atom_site_disorder_assembly _atom_site_disorder_group C1 C 0.08356(11) 0.50964(19) 0.10415(3) 0.00496(13) Uani 1 1 d . . . C2 C 0.29016(11) 0.3423(2) 0.10056(3) 0.00541(14) Uani 1 1 d . . . O2 O 0.44196(14) 0.3653(2) 0.05800(4) 0.00780(17) Uani 1 1 d . . . C3 C 0.34185(12) 0.14043(19) 0.14252(3) 0.00608(14) Uani 1 1 d . . . C4 C 0.19248(11) 0.10910(19) 0.18762(3) 0.00567(14) Uani 1 1 d . . . C5 C -0.01144(11) 0.27729(19) 0.19156(3) 0.00510(13) Uani 1 1 d . . . O5 O -0.15007(14) 0.2376(2) 0.23799(4) 0.00680(16) Uani 1 1 d . . . C6 C -0.06711(11) 0.47387(19) 0.14989(3) 0.00541(14) Uani 1 1 d . . . C7 C 0.03026(11) 0.72158(19) 0.06028(3) 0.00505(13) Uani 1 1 d . . . O8 O 0.16524(14) 0.7587(2) 0.02037(4) 0.00750(16) Uani 1 1 d . . . O9 O -0.16593(14) 0.8685(2) 0.06568(4) 0.00720(16) Uani 1 1 d . . . H6 H -0.2277(3) 0.6012(5) 0.15194(9) 0.0199(4) Uani 1 1 d . . . H3 H 0.5008(3) 0.0119(6) 0.13889(10) 0.0228(4) Uani 1 1 d . . . H4 H 0.2316(3) -0.0454(5) 0.22044(9) 0.0216(4) Uani 1 1 d . . . H5 H -0.2400(3) 0.4078(5) 0.24532(9) 0.0211(4) Uani 1 1 d . . . H1 H -0.1797(3) 1.0079(6) 0.03422(9) 0.0210(4) Uani 1 1 d . . . H2 H 0.3845(3) 0.5227(5) 0.03428(9) 0.0215(4) Uani 1 1 d . . . loop_ _atom_site_aniso_label _atom_site_aniso_U_11 _atom_site_aniso_U_22 _atom_site_aniso_U_33 _atom_site_aniso_U_23 _atom_site_aniso_U_13 _atom_site_aniso_U_12 C1 0.00495(19) 0.0065(4) 0.0035(2) 0.0009(2) 0.00078(17) 0.0005(2) C2 0.0047(2) 0.0075(4) 0.0042(2) 0.0012(2) 0.00137(17) 0.00046(19) O2 0.0066(2) 0.0108(6) 0.0064(3) 0.0017(3) 0.0031(2) 0.0013(3) C3 0.0055(2) 0.0079(4) 0.0049(2) 0.0010(2) 0.00096(17) 0.0013(2) C4 0.0055(2) 0.0073(5) 0.0043(2) 0.0014(2) 0.00067(17) 0.0012(2) C5 0.0049(2) 0.0071(4) 0.0034(2) 0.0005(2) 0.00084(16) 0.0005(2) O5 0.0074(2) 0.0082(5) 0.0051(3) 0.0011(3) 0.0027(2) 0.0005(2) C6 0.0053(2) 0.0072(4) 0.0038(2) 0.0011(2) 0.00122(17) 0.0005(2) C7 0.0052(2) 0.0061(4) 0.0039(2) 0.0009(2) 0.00061(16) -0.0001(2) O8 0.0082(2) 0.0094(5) 0.0052(3) 0.0023(3) 0.0024(2) 0.0011(3) O9 0.0067(2) 0.0093(5) 0.0058(3) 0.0023(3) 0.0014(2) 0.0018(2) H6 0.0165(6) 0.0220(12) 0.0218(8) 0.0032(7) 0.0049(5) 0.0094(6) H3 0.0175(6) 0.0275(13) 0.0239(9) 0.0045(8) 0.0052(6) 0.0121(7) H4 0.0235(7) 0.0249(13) 0.0166(8) 0.0090(7) 0.0029(6) 0.0046(7) H5 0.0242(8) 0.0195(12) 0.0206(9) 0.0014(7) 0.0086(6) 0.0057(7) H1 0.0229(7) 0.0227(12) 0.0177(8) 0.0088(8) 0.0027(6) 0.0053(7) H2 0.0255(7) 0.0237(12) 0.0160(7) 0.0090(7) 0.0074(6) 0.0037(8) _geom_special_details ; All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds involving l.s. planes. ; loop_ _geom_bond_atom_site_label_1 _geom_bond_atom_site_label_2 _geom_bond_distance C1 C6 1.4076(11) C1 C2 1.4134(12) C1 C7 1.4720(12) C2 O2 1.3469(11) C2 C3 1.4055(12) O2 H2 0.988(2) C3 C4 1.3887(11) C3 H3 1.089(2) C4 C5 1.4046(12) C4 H4 1.087(2) C5 O5 1.3816(11) C5 C6 1.3869(12) O5 H5 0.989(3) C6 H6 1.0891(19) C7 O8 1.2447(11) C7 O9 1.3154(12) O9 H1 1.000(2) loop_ _geom_angle_atom_site_label_1 _geom_angle_atom_site_label_2 _geom_angle_atom_site_label_3 _geom_angle C6 C1 C2 119.70(8) C6 C1 C7 120.82(7) C2 C1 C7 119.47(7) O2 C2 C3 117.60(7) O2 C2 C1 122.83(8) C3 C2 C1 119.56(7) C2 O2 H2 106.51(14) C4 C3 C2 120.04(7) C4 C3 H3 121.33(14) C2 C3 H3 118.63(14) C3 C4 C5 120.43(8) C3 C4 H4 120.59(13) C5 C4 H4 118.97(13) O5 C5 C6 122.49(7) O5 C5 C4 117.37(8) C6 C5 C4 120.14(7) C5 O5 H5 109.27(15) C5 C6 C1 120.10(7) C5 C6 H6 120.63(13) C1 C6 H6 119.26(14) O8 C7 O9 122.17(9) O8 C7 C1 121.29(8) O9 C7 C1 116.54(7) C7 O9 H1 108.98(14) loop_ _geom_hbond_atom_site_label_D _geom_hbond_atom_site_label_H _geom_hbond_atom_site_label_A _geom_hbond_distance_DH _geom_hbond_distance_HA _geom_hbond_distance_DA _geom_hbond_angle_DHA _geom_hbond_site_symmetry_A O5 H5 O5 0.989(3) 1.772(3) 2.7506(13) 169.8(2) 2_455 O9 H1 O8 1.000(2) 1.715(2) 2.7097(16) 172.81(18) 3_575 O2 H2 O8 0.988(2) 1.691(2) 2.5761(17) 147.09(18) . _refine_diff_density_max 0.708 _refine_diff_density_min -0.468 _refine_diff_density_rms 0.094 data_25dhoba100k _database_code_depnum_ccdc_archive 'CCDC 747947' _audit_creation_method SHELXL-97 _chemical_name_systematic ; ? ; _chemical_name_common '2,5-Dihydroxybenzoic acid' _chemical_melting_point 477 _chemical_formula_moiety 'C7 H6 O4' _chemical_formula_sum 'C7 H6 O4' _chemical_formula_weight 154.00 _symmetry_cell_setting Monoclinic _symmetry_space_group_name_H-M P21/n _symmetry_space_group_name_Hall -P2yn loop_ _symmetry_equiv_pos_as_xyz 'x, y, z' '-x+1/2, y+1/2, -z+1/2' '-x, -y, -z' 'x-1/2, -y-1/2, z-1/2' _cell_length_a 5.564(3) _cell_length_b 4.879(3) _cell_length_c 23.3903(11) _cell_angle_alpha 90.00 _cell_angle_beta 93.43(3) _cell_angle_gamma 90.00 _cell_volume 633.8(5) _cell_formula_units_Z 4 _cell_measurement_temperature 100(2) _cell_measurement_reflns_used 330 _cell_measurement_theta_min ? _cell_measurement_theta_max ? _exptl_crystal_description Block _exptl_crystal_colour colourless _exptl_crystal_size_max 7 _exptl_crystal_size_mid 3 _exptl_crystal_size_min 1 _exptl_crystal_preparation 'recrystallised from acetone solution' _exptl_crystal_density_diffrn ? _exptl_special_details ; For peak integration a local UB matrix refined for each frame, using approximately 30 reflections from each of the 11 detectors. Hence _cell_measurement_reflns_used 330 For final cell dimensions a weighted average of all local cells was calculated Because of the nature of the experiment, it is not possible to give values of theta_min and theta_max for the cell determination. The same applies for the wavelength used for the experiment. The range of wavelengths used was 0.7-6.9 Angstroms, BUT the bulk of the diffraction information is obtained from wavelengths in the range 0.8-2.9 Angstroms. The data collection procedures on the SXD instrument used for the single crystal neutron data collection are most recently summarised in the Appendix to the following paper Wilson, C.C. (1997). J. Mol. Struct. 405, 207-217. ; _diffrn_ambient_temperature 100(2) _diffrn_radiation_wavelength 0.7-6.9 _diffrn_radiation_probe neutron _diffrn_radiation_type neutron _diffrn_radiation_source 'ISIS spallation source' _diffrn_measurement_device_type 'SXD time-of-flight LAUE diffraction' _diffrn_measurement_method 'time-of-flight LAUE diffraction' _diffrn_reflns_number 8723 _diffrn_reflns_av_R_equivalents 0.0000 _diffrn_reflns_av_sigmaI/netI 0.0351 _diffrn_reflns_limit_h_min -15 _diffrn_reflns_limit_h_max 14 _diffrn_reflns_limit_k_min -8 _diffrn_reflns_limit_k_max 10 _diffrn_reflns_limit_l_min -57 _diffrn_reflns_limit_l_max 64 _reflns_number_total 8723 _reflns_number_gt 8723 _computing_data_collection SXD-2001 _computing_cell_refinement SXD-2001 _computing_data_reduction SXD-2001 _computing_structure_solution 'SHELXL-97 (Sheldrick, 1997)' _computing_structure_refinement 'SHELXL-97 (Sheldrick, 1997)' _computing_molecular_graphics SHELXTL _computing_publication_material SHELXTL _refine_special_details ; The variable wavelength nature of the data collection procedure means that sensible values of _diffrn_reflns_theta_min & _diffrn_reflns_theta_max cannot be given instead the following limits are given _diffrn_reflns_sin(theta)/lambda_min 0.09 _diffrn_reflns_sin(theta)/lambda_max 1.40 _refine_diff_density_max/min is given in Fermi per per angstrom cubed not electons per angstrom cubed. Another way to consider the _refine_diff_density_ is as a percentage of the diffracted intensity of a given atom: _refine_diff_density_max = 6.31% of Carbon _refine_diff_density_min = -3.65% of Carbon Refinement of F^2^ against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F^2^, conventional R-factors R are based on F, with F set to zero for negative F^2^. The threshold expression of F^2^ > 2sigma(F^2^) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F^2^ are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger. ; _refine_ls_hydrogen_treatment refall _refine_ls_number_reflns 8723 _refine_ls_number_parameters 264 _refine_ls_number_restraints 0 _refine_ls_R_factor_all 0.0796 _refine_ls_R_factor_gt 0.0796 _refine_ls_wR_factor_ref 0.2251 _refine_ls_wR_factor_gt 0.2251 _refine_ls_goodness_of_fit_ref 1.058 _refine_ls_shift/su_max 0.003 _refine_ls_shift/su_mean 0.001 loop_ _atom_site_label _atom_site_type_symbol _atom_site_fract_x _atom_site_fract_y _atom_site_fract_z _atom_site_U_iso_or_equiv _atom_site_adp_type _atom_site_occupancy _atom_site_symmetry_multiplicity _atom_site_calc_flag _atom_site_refinement_flags _atom_site_disorder_assembly _atom_site_disorder_group C1 C 0.08379(11) 0.5118(2) 0.10425(3) 0.00997(14) Uani 1 1 d . . . C2 C 0.29009(12) 0.3452(2) 0.10056(3) 0.01152(15) Uani 1 1 d . . . O2 O 0.44161(16) 0.3681(3) 0.05798(4) 0.0175(2) Uani 1 1 d . . . C3 C 0.34092(12) 0.1443(2) 0.14268(3) 0.01270(15) Uani 1 1 d . . . C4 C 0.19195(12) 0.1132(2) 0.18772(3) 0.01181(14) Uani 1 1 d . . . C5 C -0.01149(12) 0.2806(2) 0.19164(3) 0.00989(13) Uani 1 1 d . . . O5 O -0.14979(15) 0.2433(3) 0.23800(4) 0.01272(16) Uani 1 1 d . . . C6 C -0.06695(11) 0.4774(2) 0.14993(3) 0.00997(14) Uani 1 1 d . . . C7 C 0.03098(12) 0.7231(2) 0.06028(3) 0.01136(14) Uani 1 1 d . . . O8 O 0.16544(17) 0.7593(3) 0.02027(4) 0.0164(2) Uani 1 1 d . . . O9 O -0.16446(16) 0.8703(3) 0.06580(4) 0.01409(18) Uani 1 1 d . . . H5 H -0.2395(4) 0.4116(6) 0.24524(9) 0.0255(4) Uani 1 1 d . . . H6 H -0.2262(3) 0.6054(6) 0.15196(10) 0.0271(5) Uani 1 1 d . . . H1 H -0.1777(4) 1.0084(6) 0.03431(10) 0.0275(4) Uani 1 1 d . . . H4 H 0.2309(4) -0.0402(6) 0.22055(9) 0.0286(5) Uani 1 1 d . . . H3 H 0.4996(4) 0.0169(7) 0.13911(11) 0.0309(5) Uani 1 1 d . . . H2 H 0.3835(4) 0.5237(7) 0.03421(10) 0.0317(5) Uani 1 1 d . . . loop_ _atom_site_aniso_label _atom_site_aniso_U_11 _atom_site_aniso_U_22 _atom_site_aniso_U_33 _atom_site_aniso_U_23 _atom_site_aniso_U_13 _atom_site_aniso_U_12 C1 0.0118(2) 0.0110(4) 0.0074(2) 0.0013(2) 0.00232(16) 0.0003(2) C2 0.0116(2) 0.0135(4) 0.0098(2) 0.0009(2) 0.00338(17) 0.0006(2) O2 0.0160(3) 0.0222(7) 0.0152(4) 0.0039(4) 0.0083(2) 0.0034(3) C3 0.0122(2) 0.0152(5) 0.0109(3) 0.0015(3) 0.00230(18) 0.0029(2) C4 0.0133(2) 0.0127(4) 0.0094(2) 0.0018(2) 0.00079(18) 0.0014(2) C5 0.0117(2) 0.0108(4) 0.0074(2) 0.0006(2) 0.00185(16) -0.0002(2) O5 0.0167(3) 0.0119(5) 0.0100(3) 0.0017(3) 0.0052(2) 0.0000(3) C6 0.0117(2) 0.0106(4) 0.0079(2) 0.0019(2) 0.00268(17) 0.0009(2) C7 0.0143(2) 0.0121(4) 0.0079(2) 0.0023(2) 0.00275(17) 0.0002(2) O8 0.0194(3) 0.0193(6) 0.0112(3) 0.0051(3) 0.0066(2) 0.0027(3) O9 0.0160(3) 0.0147(6) 0.0119(3) 0.0047(3) 0.0033(2) 0.0024(3) H5 0.0300(8) 0.0224(12) 0.0251(8) 0.0017(8) 0.0113(6) 0.0052(7) H6 0.0247(7) 0.0299(14) 0.0275(9) 0.0059(8) 0.0089(6) 0.0123(8) H1 0.0328(8) 0.0259(13) 0.0239(8) 0.0091(8) 0.0040(6) 0.0044(8) H4 0.0352(9) 0.0290(14) 0.0217(8) 0.0126(8) 0.0031(6) 0.0072(9) H3 0.0245(7) 0.0351(16) 0.0338(10) 0.0043(10) 0.0070(6) 0.0131(8) H2 0.0370(9) 0.0330(16) 0.0263(9) 0.0098(9) 0.0133(7) 0.0077(9) _geom_special_details ; All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds involving l.s. planes. ; loop_ _geom_bond_atom_site_label_1 _geom_bond_atom_site_label_2 _geom_bond_distance C1 C6 1.4073(10) C1 C2 1.4134(12) C1 C7 1.4730(13) C2 O2 1.3475(12) C2 C3 1.4062(13) O2 H2 0.984(3) C3 C4 1.3873(11) C3 H3 1.087(2) C4 C5 1.4030(12) C4 H4 1.085(2) C5 O5 1.3786(11) C5 C6 1.3905(12) O5 H5 0.981(3) C6 H6 1.087(2) C7 O8 1.2452(12) C7 O9 1.3161(14) O9 H1 0.997(3) loop_ _geom_angle_atom_site_label_1 _geom_angle_atom_site_label_2 _geom_angle_atom_site_label_3 _geom_angle C6 C1 C2 120.05(8) C6 C1 C7 120.69(7) C2 C1 C7 119.26(7) O2 C2 C3 117.86(8) O2 C2 C1 122.91(9) C3 C2 C1 119.22(7) C2 O2 H2 106.43(16) C4 C3 C2 120.26(7) C4 C3 H3 121.38(16) C2 C3 H3 118.36(16) C3 C4 C5 120.47(8) C3 C4 H4 120.64(15) C5 C4 H4 118.89(14) O5 C5 C6 122.14(8) O5 C5 C4 117.71(8) C6 C5 C4 120.14(7) C5 O5 H5 109.83(16) C5 C6 C1 119.85(7) C5 C6 H6 120.88(14) C1 C6 H6 119.27(14) O8 C7 O9 122.21(10) O8 C7 C1 121.36(9) O9 C7 C1 116.43(8) C7 O9 H1 108.75(16) loop_ _geom_hbond_atom_site_label_D _geom_hbond_atom_site_label_H _geom_hbond_atom_site_label_A _geom_hbond_distance_DH _geom_hbond_distance_HA _geom_hbond_distance_DA _geom_hbond_angle_DHA _geom_hbond_site_symmetry_A O5 H5 O5 0.981(3) 1.784(3) 2.7540(15) 169.6(2) 2_455 O9 H1 O8 0.997(3) 1.712(3) 2.7049(17) 173.4(2) 3_575 O2 H2 O8 0.984(3) 1.689(3) 2.573(2) 147.4(2) . _refine_diff_density_max 0.452 _refine_diff_density_min -0.265 _refine_diff_density_rms 0.061 data_25dhoba200k _database_code_depnum_ccdc_archive 'CCDC 747948' _audit_creation_method SHELXL-97 _chemical_name_systematic ; ? ; _chemical_name_common '2,5-Dihydroxybenzoic acid' _chemical_melting_point 477 _chemical_formula_moiety 'C7 H6 O4' _chemical_formula_sum 'C7 H6 O4' _chemical_formula_weight 154.00 _symmetry_cell_setting Monoclinic _symmetry_space_group_name_H-M P21/n _symmetry_space_group_name_Hall -P2yn loop_ _symmetry_equiv_pos_as_xyz 'x, y, z' '-x+1/2, y+1/2, -z+1/2' '-x, -y, -z' 'x-1/2, -y-1/2, z-1/2' _cell_length_a 5.597(3) _cell_length_b 4.897(3) _cell_length_c 23.470(13) _cell_angle_alpha 90.00 _cell_angle_beta 92.97(4) _cell_angle_gamma 90.00 _cell_volume 642.4(6) _cell_formula_units_Z 4 _cell_measurement_temperature 200(2) _cell_measurement_reflns_used 330 _exptl_crystal_description Block _exptl_crystal_colour colourless _exptl_crystal_size_max 7 _exptl_crystal_size_mid 3 _exptl_crystal_size_min 1 _exptl_crystal_preparation 'recrystallised from acetone solution' _exptl_crystal_density_diffrn ? _exptl_special_details ; For peak integration a local UB matrix refined for each frame, using approximately 30 reflections from each of the 11 detectors. Hence _cell_measurement_reflns_used 330 For final cell dimensions a weighted average of all local cells was calculated Because of the nature of the experiment, it is not possible to give values of theta_min and theta_max for the cell determination. The same applies for the wavelength used for the experiment. The range of wavelengths used was 0.7-6.9 Angstroms, BUT the bulk of the diffraction information is obtained from wavelengths in the range 0.8-2.9 Angstroms. The data collection procedures on the SXD instrument used for the single crystal neutron data collection are most recently summarised in the Appendix to the following paper Wilson, C.C. (1997). J. Mol. Struct. 405, 207-217. ; _diffrn_ambient_temperature 200(2) _diffrn_radiation_wavelength 0.7-6.9 _diffrn_radiation_probe neutron _diffrn_radiation_type neutron _diffrn_radiation_source 'ISIS spallation source' _diffrn_measurement_device_type 'SXD time-of-flight LAUE diffraction' _diffrn_measurement_method 'time-of-flight LAUE diffraction' _diffrn_reflns_number 8249 _diffrn_reflns_av_R_equivalents 0.0000 _diffrn_reflns_av_sigmaI/netI 0.0361 _diffrn_reflns_limit_h_min -11 _diffrn_reflns_limit_h_max 11 _diffrn_reflns_limit_k_min -7 _diffrn_reflns_limit_k_max 9 _diffrn_reflns_limit_l_min -37 _diffrn_reflns_limit_l_max 63 _reflns_number_total 8249 _reflns_number_gt 8249 _computing_data_collection SXD-2001 _computing_cell_refinement SXD-2001 _computing_data_reduction SXD-2001 _computing_structure_solution 'SHELXL-97 (Sheldrick, 1997)' _computing_structure_refinement 'SHELXL-97 (Sheldrick, 1997)' _computing_molecular_graphics SHELXTL _computing_publication_material SHELXTL _refine_special_details ; The variable wavelength nature of the data collection procedure means that sensible values of _diffrn_reflns_theta_min & _diffrn_reflns_theta_max cannot be given instead the following limits are given _diffrn_reflns_sin(theta)/lambda_min 0.09 _diffrn_reflns_sin(theta)/lambda_max 1.36 _refine_diff_density_max/min is given in Fermi per per angstrom cubed not electons per angstrom cubed. Another way to consider the _refine_diff_density_ is as a percentage of the diffracted intensity of a given atom: _refine_diff_density_max = 6.70% of Carbon _refine_diff_density_min = -3.79% of Carbon Refinement of F^2^ against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F^2^, conventional R-factors R are based on F, with F set to zero for negative F^2^. The threshold expression of F^2^ > 2sigma(F^2^) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F^2^ are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger. ; _refine_ls_hydrogen_treatment refall _refine_ls_number_reflns 8249 _refine_ls_number_parameters 286 _refine_ls_number_restraints 0 _refine_ls_R_factor_all 0.0815 _refine_ls_R_factor_gt 0.0815 _refine_ls_wR_factor_ref 0.2300 _refine_ls_wR_factor_gt 0.2300 _refine_ls_goodness_of_fit_ref 0.978 _refine_ls_shift/su_max 0.001 _refine_ls_shift/su_mean 0.000 loop_ _atom_site_label _atom_site_type_symbol _atom_site_fract_x _atom_site_fract_y _atom_site_fract_z _atom_site_U_iso_or_equiv _atom_site_adp_type _atom_site_occupancy _atom_site_symmetry_multiplicity _atom_site_calc_flag _atom_site_refinement_flags _atom_site_disorder_assembly _atom_site_disorder_group C1 C 0.08413(14) 0.5162(2) 0.10436(3) 0.01818(17) Uani 1 1 d . . . C2 C 0.28898(15) 0.3514(2) 0.10069(4) 0.0212(2) Uani 1 1 d . . . O2 O 0.4407(2) 0.3726(4) 0.05815(6) 0.0328(3) Uani 1 1 d . . . C3 C 0.33904(15) 0.1520(3) 0.14278(4) 0.0233(2) Uani 1 1 d . . . C4 C 0.19033(15) 0.1229(2) 0.18779(4) 0.02138(19) Uani 1 1 d . . . C5 C -0.01155(14) 0.2893(2) 0.19166(3) 0.01818(17) Uani 1 1 d . . . O5 O -0.1501(2) 0.2517(3) 0.23799(4) 0.0243(2) Uani 1 1 d . . . C6 C -0.06590(14) 0.4839(2) 0.15002(4) 0.01822(17) Uani 1 1 d . . . C7 C 0.03230(15) 0.7258(2) 0.06030(4) 0.02100(19) Uani 1 1 d . . . O8 O 0.1657(2) 0.7602(3) 0.02031(5) 0.0305(3) Uani 1 1 d . . . O9 O -0.1623(2) 0.8715(3) 0.06586(5) 0.0266(3) Uani 1 1 d . . . H4 H 0.2290(5) -0.0281(7) 0.22077(11) 0.0429(6) Uani 1 1 d . . . H6 H -0.2238(4) 0.6107(6) 0.15222(11) 0.0377(5) Uani 1 1 d . . . H5 H -0.2388(4) 0.4200(6) 0.24489(10) 0.0369(5) Uani 1 1 d . . . H1 H -0.1752(5) 1.0100(6) 0.03454(11) 0.0394(5) Uani 1 1 d . . . H3 H 0.4959(4) 0.0236(7) 0.13901(13) 0.0467(7) Uani 1 1 d . . . H2 H 0.3834(5) 0.5265(8) 0.03414(12) 0.0481(7) Uani 1 1 d . . . loop_ _atom_site_aniso_label _atom_site_aniso_U_11 _atom_site_aniso_U_22 _atom_site_aniso_U_33 _atom_site_aniso_U_23 _atom_site_aniso_U_13 _atom_site_aniso_U_12 C1 0.0223(3) 0.0189(5) 0.0138(3) 0.0022(3) 0.0052(2) 0.0001(3) C2 0.0218(3) 0.0236(6) 0.0187(4) 0.0017(3) 0.0068(3) 0.0023(3) O2 0.0313(5) 0.0393(9) 0.0294(6) 0.0086(6) 0.0167(4) 0.0077(5) C3 0.0216(3) 0.0270(6) 0.0216(4) 0.0033(4) 0.0045(3) 0.0047(3) C4 0.0248(3) 0.0221(6) 0.0173(3) 0.0035(3) 0.0019(3) 0.0027(3) C5 0.0237(3) 0.0183(5) 0.0129(3) 0.0014(3) 0.0039(2) -0.0003(3) O5 0.0335(5) 0.0227(7) 0.0175(4) 0.0042(4) 0.0104(3) 0.0014(4) C6 0.0224(3) 0.0192(5) 0.0136(3) 0.0027(3) 0.0056(2) 0.0018(3) C7 0.0272(4) 0.0213(6) 0.0150(3) 0.0033(3) 0.0061(3) -0.0002(3) O8 0.0380(5) 0.0332(8) 0.0216(5) 0.0108(5) 0.0143(4) 0.0053(5) O9 0.0315(4) 0.0277(8) 0.0213(4) 0.0091(4) 0.0071(3) 0.0046(4) H4 0.0517(12) 0.0447(18) 0.0324(11) 0.0165(10) 0.0031(9) 0.0122(11) H6 0.0376(9) 0.0380(15) 0.0385(11) 0.0087(10) 0.0135(8) 0.0154(9) H5 0.0468(11) 0.0338(14) 0.0314(10) 0.0025(9) 0.0151(8) 0.0058(10) H1 0.0526(11) 0.0344(15) 0.0317(10) 0.0122(9) 0.0065(8) 0.0054(10) H3 0.0377(10) 0.052(2) 0.0512(14) 0.0090(13) 0.0115(9) 0.0191(11) H2 0.0529(12) 0.054(2) 0.0390(12) 0.0162(12) 0.0208(10) 0.0098(12) _geom_special_details ; All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds involving l.s. planes. ; loop_ _geom_bond_atom_site_label_1 _geom_bond_atom_site_label_2 _geom_bond_distance C1 C6 1.4044(13) C1 C2 1.4083(14) C1 C7 1.4751(15) C2 O2 1.3478(16) C2 C3 1.4068(16) O2 H2 0.984(4) C3 C4 1.3857(14) C3 H3 1.087(3) C4 C5 1.3999(14) C4 H4 1.084(3) C5 O5 1.3803(14) C5 C6 1.3872(14) O5 H5 0.980(3) C6 H6 1.084(2) C7 O8 1.2407(15) C7 O9 1.3144(17) O9 H1 1.000(3) loop_ _geom_angle_atom_site_label_1 _geom_angle_atom_site_label_2 _geom_angle_atom_site_label_3 _geom_angle C6 C1 C2 120.20(9) C6 C1 C7 120.65(8) C2 C1 C7 119.14(8) O2 C2 C3 117.61(10) O2 C2 C1 123.19(10) C3 C2 C1 119.20(8) C2 O2 H2 106.50(19) C4 C3 C2 120.08(9) C4 C3 H3 121.46(19) C2 C3 H3 118.46(18) C3 C4 C5 120.54(9) C3 C4 H4 120.59(17) C5 C4 H4 118.86(17) O5 C5 C6 122.33(9) O5 C5 C4 117.50(10) C6 C5 C4 120.16(8) C5 O5 H5 109.15(18) C5 C6 C1 119.80(8) C5 C6 H6 120.65(15) C1 C6 H6 119.55(15) O8 C7 O9 122.40(12) O8 C7 C1 121.37(10) O9 C7 C1 116.23(9) C7 O9 H1 108.88(19) loop_ _geom_hbond_atom_site_label_D _geom_hbond_atom_site_label_H _geom_hbond_atom_site_label_A _geom_hbond_distance_DH _geom_hbond_distance_HA _geom_hbond_distance_DA _geom_hbond_angle_DHA _geom_hbond_site_symmetry_A O5 H5 O5 0.980(3) 1.792(3) 2.7619(16) 169.7(2) 2_455 O9 H1 O8 1.000(3) 1.713(3) 2.709(2) 173.8(2) 3_575 O2 H2 O8 0.984(4) 1.691(3) 2.573(2) 146.9(2) . _refine_diff_density_max 0.305 _refine_diff_density_min -0.168 _refine_diff_density_rms 0.038