This journal is © The Royal Society of Chemistry 2002 data_global _journal_coden_Cambridge 1355 _publ_requested_journal 'Faraday Discussions' loop_ _publ_author_name 'Harrison, Andrew' 'Ibberson, R.' 'Robb, Graeme' 'Whittaker, Gavin' 'Wilson, C.' 'Youngson, Douglas' _publ_contact_author_name 'Prof Andrew Harrison' _publ_contact_author_address ; Chemistry The University of Edinburgh King's Buildings West Mains Rd. Edinburgh EH18 1AF UNITED KINGDOM ; _publ_contact_author_email 'A.HARRISON@ED.AC.UK' _publ_section_title ; In situ neutron diffraction studies of single crystals and powders during microwave irradiation ; data_asp100 _database_code_CSD 185472 _audit_creation_method SHELXL-97 _chemical_name_systematic ; 2-(acetoyloxy)benzoic acid ; _chemical_name_common Aspirin _chemical_formula_sum 'C9 H8 O4' _chemical_formula_weight 180.16 loop_ _atom_type_symbol _atom_type_description _atom_type_scat_length_neutron _atom_type_scat_source 'C' 'C' 6.646 'International Tables Vol C Table 4.4.4.1' 'H' 'H' -3.739 'International Tables Vol C Table 4.4.4.1' 'O' 'O' 5.803 'International Tables Vol C Table 4.4.4.1' _symmetry_cell_setting Monoclinic _symmetry_space_group_name_H-M 'P21/c' loop_ _symmetry_equiv_pos_as_xyz 'x, y, z' '-x, y+1/2, -z+1/2' '-x, -y, -z' 'x, -y-1/2, z-1/2' _cell_length_a 11.233(3) _cell_length_b 6.5440(10) _cell_length_c 11.231(3) _cell_angle_alpha 90.00 _cell_angle_beta 95.89(2) _cell_angle_gamma 90.00 _cell_volume 821.2(3) _cell_formula_units_Z 4 _cell_measurement_temperature 100(1) _cell_measurement_reflns_used 25 _cell_measurement_theta_min ? _cell_measurement_theta_min ? _exptl_crystal_description 'irregular prism' _exptl_crystal_colour colourless _exptl_crystal_size_max 8 _exptl_crystal_size_mid 4 _exptl_crystal_size_min 1.5 _exptl_crystal_density_meas ? _exptl_crystal_density_diffrn 1.456 _exptl_crystal_density_method 'not measured' _exptl_crystal_F_000 21 _exptl_absorpt_coefficient_mu '1.0550, at 1 Angstrom' _exptl_absorpt_correction_type empirical _exptl_absorpt_correction_T_min 0.45 _exptl_absorpt_correction_T_max 0.75 _exptl_absorpt_process_details ; The linear absorption coefficient is wavelength dependent and it is calculated as: mu = 0.80 + 0.75 * lambda [cm^-1] ; _exptl_special_details ; For peak integration a local UB matrix refined for each frame, using approximately 25 reflections. Hence _cell_measurement_reflns_used 25 For final cell dimensions an average of all local cells was performed and estimated standard uncertainties were obtained from the spread of the local observations Because of the nature of the experiment, it is not possible to give values of theta_min and theta_max for the cell determination. Instead, we can give values of #_cell_measurement_sin(theta)/lambda_min 0.20 #_cell_measurement_sin(theta)/lambda_max 0.75 The same applies for the wavelength used for the experiment. The range of wavelengths used was 0.5-5.0 Angstroms, BUT the bulk of the diffraction information is obtained from wavelengths in the range 0.7-2.5 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 0.5-5.0 _diffrn_radiation_type neutron _diffrn_radiation_source 'ISIS spallation source' _diffrn_measurement_device SXD _diffrn_measurement_method 'time-of-flight LAUE diffraction' _diffrn_reflns_number 3971 _diffrn_reflns_av_R_equivalents 0.068 _diffrn_reflns_av_sigmaI/netI 0.0414 _diffrn_reflns_limit_h_min 0 _diffrn_reflns_limit_h_max 24 _diffrn_reflns_limit_k_min 0 _diffrn_reflns_limit_k_max 14 _diffrn_reflns_limit_l_min -16 _diffrn_reflns_limit_l_max 18 _diffrn_reflns_theta_min ? _diffrn_reflns_theta_max ? _reflns_number_total 1151 _reflns_number_gt 1151 _reflns_threshold_expression >2sigma(I) _computing_data_collection ? _computing_cell_refinement ? _computing_data_reduction ? _computing_structure_solution ? _computing_structure_refinement 'SHELXL-97 (Sheldrick, 1997)' _computing_molecular_graphics 'ORTEP (Johnson, 1994)' _computing_publication_material ? _refine_special_details ; These data are by no means complete. They were collected in a very restricted geometry due to the microwave apparatus also installed at the time. The data/parameter ratio is also rather small, however the refinements are stable and supportive of the observations presented in the paper. The microwave source was switched OFF for these data. 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 It is also difficult to estimate realistic values of maximum sin(theta)/lambda values for two reasons: (i) Different sin(theta)/lambda ranges are accessed in different parts of the detectors (ii) The nature of the data collection occasionally allows some reflections at very high sin(theta)/lambda to be observed even when no real attempt has been made to measure data in this region. However, we can attempt to estimate the sin(theta)/lambda limits as follows: #_diffrn_reflns_sin(theta)/lambda_min 0.05 #_diffrn_reflns_sin(theta)/lambda_max 0.75 Note also that reflections for which the standard profile fitting integration procedure fails are excluded from the data set, thus resulting in a high elimination rate of weak or "unobserved" peaks from the final data set. The extinction coefficient reported in _refine_ls_extinction_coef is in this case the refined value of the mosaic spread in units of 10^-4 rad^-1 The reference for the extinction method used is: Becker, P. & Coppens, P. (1974). Acta Cryst. A30, 129-148. 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_structure_factor_coef Fsqd _refine_ls_matrix_type full _refine_ls_weighting_scheme calc _refine_ls_weighting_details 'calc w=1/[\s^2^(Fo^2^)+(0.0763P)^2^+0.3996P] where P=(Fo^2^+2Fc^2^)/3' _refine_ls_hydrogen_treatment refall _refine_ls_extinction_method 'Becker-Coppens Lorentzian model' _refine_ls_extinction_coef 0.06 _refine_ls_number_reflns 1151 _refine_ls_number_parameters 190 _refine_ls_number_restraints 0 _refine_ls_R_factor_all 0.0958 _refine_ls_R_factor_gt 0.0958 _refine_ls_wR_factor_ref 0.2369 _refine_ls_wR_factor_gt 0.2369 _refine_ls_goodness_of_fit_ref 1.468 _refine_ls_restrained_S_all 1.468 _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 0.1537(4) 0.5603(6) 0.0665(6) 0.0115(9) Uani 1 1 d . . . C2 C 0.2473(4) 0.4838(6) 0.0088(5) 0.0118(10) Uani 1 1 d . . . C3 C 0.2998(4) 0.2977(7) 0.0414(7) 0.0174(12) Uani 1 1 d . . . C4 C 0.2609(4) 0.1876(7) 0.1352(7) 0.0199(12) Uani 1 1 d . . . C5 C 0.1686(4) 0.2620(7) 0.1942(7) 0.0174(12) Uani 1 1 d . . . C6 C 0.1158(4) 0.4463(7) 0.1614(6) 0.0158(11) Uani 1 1 d . . . C7 C 0.0903(4) 0.7562(7) 0.0372(5) 0.0113(9) Uani 1 1 d . . . C8 C 0.3674(4) 0.7373(7) -0.0623(6) 0.0137(10) Uani 1 1 d . . . C9 C 0.3993(5) 0.8399(9) -0.1740(7) 0.0214(12) Uani 1 1 d . . . O1 O 0.1235(5) 0.8590(10) -0.0527(9) 0.0201(15) Uani 1 1 d . . . O2 O 0.0098(6) 0.8130(9) 0.0966(8) 0.0205(13) Uani 1 1 d . . . O3 O 0.2886(5) 0.5827(8) -0.0890(7) 0.0136(11) Uani 1 1 d . . . O4 O 0.4029(6) 0.7815(11) 0.0367(8) 0.0248(16) Uani 1 1 d . . . H1 H 0.3698(11) 0.2377(19) -0.0095(17) 0.035(3) Uani 1 1 d . . . H2 H 0.3016(12) 0.0396(16) 0.1593(16) 0.033(3) Uani 1 1 d . . . H3 H 0.1406(11) 0.174(2) 0.2688(19) 0.040(4) Uani 1 1 d . . . H4 H 0.0433(10) 0.507(2) 0.2083(16) 0.031(3) Uani 1 1 d . . . H5 H 0.4618(18) 0.960(3) -0.145(3) 0.059(6) Uani 1 1 d . . . H6 H 0.3200(16) 0.897(5) -0.224(3) 0.088(12) Uani 1 1 d . . . H7 H 0.434(3) 0.735(4) -0.240(3) 0.072(7) Uani 1 1 d . . . H8 H 0.0713(10) 0.9855(18) -0.0642(15) 0.030(3) 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 0.0116(13) 0.0103(15) 0.013(3) 0.0003(14) 0.0039(19) 0.0000(11) C2 0.0125(14) 0.0133(17) 0.010(3) -0.0038(14) 0.0035(19) 0.0000(11) C3 0.0186(17) 0.0144(19) 0.020(4) -0.0003(18) 0.007(2) 0.0048(13) C4 0.0183(18) 0.0138(19) 0.028(4) 0.0034(19) 0.006(2) 0.0039(13) C5 0.0132(15) 0.0177(19) 0.022(4) 0.0047(19) 0.006(2) 0.0016(13) C6 0.0143(15) 0.0155(18) 0.018(3) 0.0037(17) 0.005(2) 0.0013(13) C7 0.0127(14) 0.0126(18) 0.009(3) 0.0005(15) 0.0044(17) 0.0025(11) C8 0.0103(13) 0.0199(19) 0.012(3) -0.0024(17) 0.0050(18) -0.0027(12) C9 0.023(2) 0.029(3) 0.013(4) 0.003(2) 0.006(3) -0.0061(17) O1 0.0166(19) 0.022(2) 0.023(5) 0.008(2) 0.006(3) 0.0058(16) O2 0.025(2) 0.018(2) 0.021(4) 0.006(2) 0.012(3) 0.0093(17) O3 0.0163(18) 0.014(2) 0.011(3) -0.0052(18) 0.002(2) -0.0008(14) O4 0.027(3) 0.032(3) 0.015(5) -0.007(3) 0.006(3) -0.013(2) H1 0.033(5) 0.031(6) 0.040(10) 0.001(5) 0.005(6) 0.010(4) H2 0.047(6) 0.018(4) 0.036(10) 0.009(4) 0.010(7) 0.011(4) H3 0.028(5) 0.041(6) 0.052(12) 0.030(7) 0.009(7) 0.007(4) H4 0.027(4) 0.039(6) 0.028(9) 0.006(5) 0.009(6) 0.004(4) H5 0.062(9) 0.054(10) 0.063(19) -0.002(9) 0.017(12) -0.026(7) H6 0.040(8) 0.115(18) 0.10(3) 0.081(19) -0.030(12) -0.016(9) H7 0.13(2) 0.072(14) 0.024(15) -0.007(9) 0.045(15) -0.004(12) H8 0.031(4) 0.030(5) 0.031(9) 0.009(5) 0.009(6) 0.009(4) _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 _geom_bond_site_symmetry_2 _geom_bond_publ_flag C1 C2 1.385(7) . ? C1 C6 1.402(9) . ? C1 C7 1.487(6) . ? C2 C3 1.386(6) . ? C2 O3 1.394(10) . ? C3 C4 1.384(10) . ? C3 H1 1.091(16) . ? C4 C5 1.376(9) . ? C4 H2 1.093(11) . ? C5 C6 1.377(7) . ? C5 H3 1.091(17) . ? C6 H4 1.089(16) . ? C7 O2 1.235(9) . ? C7 O1 1.299(10) . ? C8 O4 1.177(11) . ? C8 O3 1.358(7) . ? C8 C9 1.499(10) . ? C9 H5 1.083(18) . ? C9 H6 1.069(17) . ? C9 H7 1.11(3) . ? O1 H8 1.016(12) . ? 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 117.9(4) . . ? C2 C1 C7 125.3(5) . . ? C6 C1 C7 116.8(4) . . ? C1 C2 C3 121.1(5) . . ? C1 C2 O3 122.1(5) . . ? C3 C2 O3 116.7(5) . . ? C4 C3 C2 120.0(5) . . ? C4 C3 H1 120.8(9) . . ? C2 C3 H1 119.2(10) . . ? C5 C4 C3 119.7(5) . . ? C5 C4 H2 120.7(11) . . ? C3 C4 H2 119.6(10) . . ? C4 C5 C6 120.4(6) . . ? C4 C5 H3 118.2(9) . . ? C6 C5 H3 121.3(9) . . ? C5 C6 C1 120.9(5) . . ? C5 C6 H4 120.8(9) . . ? C1 C6 H4 118.3(8) . . ? O2 C7 O1 123.3(5) . . ? O2 C7 C1 120.0(5) . . ? O1 C7 C1 116.7(5) . . ? O4 C8 O3 122.8(7) . . ? O4 C8 C9 126.4(6) . . ? O3 C8 C9 110.8(6) . . ? C8 C9 H5 105.8(16) . . ? C8 C9 H6 109.5(15) . . ? H5 C9 H6 113(2) . . ? C8 C9 H7 114.4(15) . . ? H5 C9 H7 113(2) . . ? H6 C9 H7 101(3) . . ? C7 O1 H8 108.2(11) . . ? C8 O3 C2 115.7(6) . . ? _refine_diff_density_max 0.174 _refine_diff_density_min -0.169 _refine_diff_density_rms 0.041 data_asp100mw _database_code_CSD 185473 _audit_creation_method SHELXL-97 _chemical_name_systematic ; 2-(acetoyloxy)benzoic acid ; _chemical_name_common Aspirin _chemical_formula_sum 'C9 H8 O4' _chemical_formula_weight 180.16 loop_ _atom_type_symbol _atom_type_description _atom_type_scat_length_neutron _atom_type_scat_source 'C' 'C' 6.646 'International Tables Vol C Table 4.4.4.1' 'H' 'H' -3.739 'International Tables Vol C Table 4.4.4.1' 'O' 'O' 5.803 'International Tables Vol C Table 4.4.4.1' _symmetry_cell_setting Monoclinic _symmetry_space_group_name_H-M 'P21/c' loop_ _symmetry_equiv_pos_as_xyz 'x, y, z' '-x, y+1/2, -z+1/2' '-x, -y, -z' 'x, -y-1/2, z-1/2' _cell_length_a 11.233(3) _cell_length_b 6.5440(10) _cell_length_c 11.231(3) _cell_angle_alpha 90.00 _cell_angle_beta 95.89(2) _cell_angle_gamma 90.00 _cell_volume 821.2(3) _cell_formula_units_Z 4 _cell_measurement_temperature 100(1) _cell_measurement_reflns_used 25 _cell_measurement_theta_min ? _cell_measurement_theta_min ? _exptl_crystal_description 'irregular prism' _exptl_crystal_colour colourless _exptl_crystal_size_max 8 _exptl_crystal_size_mid 4 _exptl_crystal_size_min 1.5 _exptl_crystal_density_meas ? _exptl_crystal_density_diffrn 1.456 _exptl_crystal_density_method 'not measured' _exptl_crystal_F_000 21 _exptl_absorpt_coefficient_mu '1.0550, at 1 Angstrom' _exptl_absorpt_correction_type empirical _exptl_absorpt_correction_T_min 0.45 _exptl_absorpt_correction_T_max 0.75 _exptl_absorpt_process_details ; The linear absorption coefficient is wavelength dependent and it is calculated as: mu = 0.80 + 0.75 * lambda [cm^-1] ; _exptl_special_details ; For peak integration a local UB matrix refined for each frame, using approximately 25 reflections. Hence _cell_measurement_reflns_used 25 For final cell dimensions an average of all local cells was performed and estimated standard uncertainties were obtained from the spread of the local observations Because of the nature of the experiment, it is not possible to give values of theta_min and theta_max for the cell determination. Instead, we can give values of #_cell_measurement_sin(theta)/lambda_min 0.20 #_cell_measurement_sin(theta)/lambda_max 0.75 The same applies for the wavelength used for the experiment. The range of wavelengths used was 0.5-5.0 Angstroms, BUT the bulk of the diffraction information is obtained from wavelengths in the range 0.7-2.5 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 0.5-5.0 _diffrn_radiation_type neutron _diffrn_radiation_source 'ISIS spallation source' _diffrn_measurement_device SXD _diffrn_measurement_method 'time-of-flight LAUE diffraction' _diffrn_reflns_number 3325 _diffrn_reflns_av_R_equivalents 0.095 _diffrn_reflns_av_sigmaI/netI 0.0361 _diffrn_reflns_limit_h_min 0 _diffrn_reflns_limit_h_max 23 _diffrn_reflns_limit_k_min 0 _diffrn_reflns_limit_k_max 12 _diffrn_reflns_limit_l_min -15 _diffrn_reflns_limit_l_max 16 _diffrn_reflns_theta_min ? _diffrn_reflns_theta_max ? _reflns_number_total 766 _reflns_number_gt 766 _reflns_threshold_expression >2sigma(I) _computing_data_collection ? _computing_cell_refinement ? _computing_data_reduction ? _computing_structure_solution ? _computing_structure_refinement 'SHELXL-97 (Sheldrick, 1997)' _computing_molecular_graphics 'ORTEP (Johnson, 1994)' _computing_publication_material ? _refine_special_details ; These data are by no means complete. They were collected in a very restricted geometry due to the microwave apparatus also installed at the time. The data/parameter ratio is also rather small, however the refinements are stable and supportive of the observations presented in the paper. The microwave source was switched ON for these data. 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 It is also difficult to estimate realistic values of maximum sin(theta)/lambda values for two reasons: (i) Different sin(theta)/lambda ranges are accessed in different parts of the detectors (ii) The nature of the data collection occasionally allows some reflections at very high sin(theta)/lambda to be observed even when no real attempt has been made to measure data in this region. However, we can attempt to estimate the sin(theta)/lambda limits as follows: #_diffrn_reflns_sin(theta)/lambda_min 0.05 #_diffrn_reflns_sin(theta)/lambda_max 0.70 Note also that reflections for which the standard profile fitting integration procedure fails are excluded from the data set, thus resulting in a high elimination rate of weak or "unobserved" peaks from the final data set. The extinction coefficient reported in _refine_ls_extinction_coef is in this case the refined value of the mosaic spread in units of 10^-4 rad^-1 The reference for the extinction method used is: Becker, P. & Coppens, P. (1974). Acta Cryst. A30, 129-148. 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_structure_factor_coef Fsqd _refine_ls_matrix_type full _refine_ls_weighting_scheme calc _refine_ls_weighting_details 'calc w=1/[\s^2^(Fo^2^)+(0.0763P)^2^+0.3996P] where P=(Fo^2^+2Fc^2^)/3' _refine_ls_hydrogen_treatment refall _refine_ls_extinction_method 'Becker-Coppens Lorentzian model' _refine_ls_extinction_coef 0.06 _refine_ls_number_reflns 766 _refine_ls_number_parameters 190 _refine_ls_number_restraints 0 _refine_ls_R_factor_all 0.1302 _refine_ls_R_factor_gt 0.1302 _refine_ls_wR_factor_ref 0.3090 _refine_ls_wR_factor_gt 0.3090 _refine_ls_goodness_of_fit_ref 1.764 _refine_ls_restrained_S_all 1.764 _refine_ls_shift/su_max 0.000 _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 0.1526(8) 0.5638(16) 0.0676(12) 0.030(3) Uani 1 1 d . . . C2 C 0.2462(7) 0.4861(18) 0.0075(11) 0.033(3) Uani 1 1 d . . . C3 C 0.2983(9) 0.3039(15) 0.0403(14) 0.040(3) Uani 1 1 d . . . C4 C 0.2599(10) 0.1957(19) 0.1334(14) 0.043(3) Uani 1 1 d . . . C5 C 0.1706(9) 0.2672(17) 0.1941(12) 0.035(3) Uani 1 1 d . . . C6 C 0.1168(8) 0.4454(16) 0.1600(13) 0.037(3) Uani 1 1 d . . . C7 C 0.0904(8) 0.7579(14) 0.0378(11) 0.031(3) Uani 1 1 d . . . C8 C 0.3651(8) 0.7386(17) -0.0640(12) 0.035(3) Uani 1 1 d . . . C9 C 0.3968(12) 0.841(2) -0.1730(18) 0.048(4) Uani 1 1 d . . . O1 O 0.1197(11) 0.858(2) -0.0513(17) 0.044(4) Uani 1 1 d . . . O2 O 0.0112(12) 0.8114(19) 0.0969(17) 0.044(4) Uani 1 1 d . . . O3 O 0.2854(10) 0.5848(19) -0.0875(13) 0.032(3) Uani 1 1 d . . . O4 O 0.4028(12) 0.780(2) 0.0338(17) 0.049(4) Uani 1 1 d . . . H1 H 0.372(2) 0.239(4) -0.005(3) 0.060(8) Uani 1 1 d . . . H2 H 0.304(2) 0.046(4) 0.156(3) 0.065(9) Uani 1 1 d . . . H3 H 0.141(2) 0.173(4) 0.277(3) 0.057(7) Uani 1 1 d . . . H4 H 0.044(2) 0.510(4) 0.207(3) 0.051(7) Uani 1 1 d . . . H5 H 0.468(3) 0.942(7) -0.142(5) 0.100(15) Uani 1 1 d . . . H6 H 0.326(4) 0.875(12) -0.235(6) 0.15(3) Uani 1 1 d . . . H7 H 0.440(5) 0.713(8) -0.231(7) 0.13(3) Uani 1 1 d . . . H8 H 0.071(2) 0.998(5) -0.065(4) 0.068(9) 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 0.028(4) 0.032(5) 0.030(9) 0.004(4) -0.004(4) 0.000(4) C2 0.025(4) 0.052(6) 0.022(9) -0.008(5) 0.000(4) -0.001(4) C3 0.038(5) 0.025(5) 0.059(11) -0.001(5) 0.009(5) 0.010(4) C4 0.044(5) 0.038(6) 0.048(12) 0.015(5) 0.007(5) 0.005(4) C5 0.040(5) 0.039(6) 0.028(10) 0.009(5) 0.010(5) 0.002(4) C6 0.034(4) 0.039(6) 0.037(10) 0.005(5) 0.007(5) 0.005(4) C7 0.029(4) 0.018(4) 0.044(9) -0.007(4) -0.003(4) 0.005(3) C8 0.032(4) 0.043(6) 0.030(10) -0.004(5) 0.003(4) 0.000(4) C9 0.049(6) 0.058(8) 0.037(12) 0.011(6) 0.008(6) -0.012(6) O1 0.046(6) 0.038(7) 0.050(14) 0.020(6) 0.008(7) 0.008(5) O2 0.054(7) 0.029(6) 0.052(14) 0.010(5) 0.019(7) 0.014(5) O3 0.036(5) 0.046(7) 0.016(10) -0.006(5) 0.012(5) -0.007(4) O4 0.050(7) 0.067(10) 0.031(12) 0.000(7) 0.004(6) -0.020(6) H1 0.054(12) 0.070(16) 0.06(3) 0.009(13) 0.037(13) 0.027(11) H2 0.076(15) 0.053(16) 0.07(3) 0.003(14) 0.026(15) 0.025(12) H3 0.084(16) 0.051(15) 0.04(2) 0.005(11) 0.021(13) 0.000(11) H4 0.063(12) 0.061(14) 0.04(2) 0.013(12) 0.036(11) 0.018(10) H5 0.09(2) 0.12(3) 0.10(5) -0.02(2) 0.04(2) -0.04(2) H6 0.10(3) 0.26(7) 0.08(5) 0.10(5) -0.02(3) -0.06(4) H7 0.15(4) 0.11(4) 0.16(8) -0.04(4) 0.11(4) -0.02(3) H8 0.064(14) 0.069(17) 0.08(3) 0.008(15) 0.032(14) 0.014(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 _geom_bond_site_symmetry_2 _geom_bond_publ_flag C1 C6 1.387(17) . ? C1 C2 1.402(16) . ? C1 C7 1.472(14) . ? C2 O3 1.358(19) . ? C2 C3 1.362(15) . ? C3 C4 1.369(19) . ? C3 H1 1.10(2) . ? C4 C5 1.35(2) . ? C4 H2 1.12(3) . ? C5 C6 1.351(15) . ? C5 H3 1.19(3) . ? C6 H4 1.10(3) . ? C7 O2 1.215(19) . ? C7 O1 1.27(2) . ? C8 O4 1.17(2) . ? C8 O3 1.355(16) . ? C8 C9 1.47(2) . ? C9 H5 1.07(4) . ? C9 H6 1.03(5) . ? C9 H7 1.19(5) . ? O1 H8 1.06(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 C6 C1 C2 116.6(10) . . ? C6 C1 C7 119.0(10) . . ? C2 C1 C7 124.4(10) . . ? O3 C2 C3 117.6(11) . . ? O3 C2 C1 121.7(11) . . ? C3 C2 C1 120.7(12) . . ? C2 C3 C4 119.9(12) . . ? C2 C3 H1 122.4(19) . . ? C4 C3 H1 117.7(18) . . ? C5 C4 C3 121.0(11) . . ? C5 C4 H2 122(2) . . ? C3 C4 H2 117(2) . . ? C6 C5 C4 119.3(12) . . ? C6 C5 H3 121.3(17) . . ? C4 C5 H3 119.5(16) . . ? C5 C6 C1 122.6(11) . . ? C5 C6 H4 121.9(17) . . ? C1 C6 H4 115.4(16) . . ? O2 C7 O1 123.1(13) . . ? O2 C7 C1 118.7(12) . . ? O1 C7 C1 118.1(11) . . ? O4 C8 O3 121.6(15) . . ? O4 C8 C9 125.7(13) . . ? O3 C8 C9 112.7(12) . . ? C8 C9 H5 104(3) . . ? C8 C9 H6 115(3) . . ? H5 C9 H6 126(5) . . ? C8 C9 H7 107(3) . . ? H5 C9 H7 107(4) . . ? H6 C9 H7 96(6) . . ? C7 O1 H8 113(3) . . ? C8 O3 C2 117.4(12) . . ? _refine_diff_density_max 0.151 _refine_diff_density_min -0.122 _refine_diff_density_rms 0.035 data_asp200 _database_code_CSD 185474 _audit_creation_method SHELXL-97 _chemical_name_systematic ; 2-(acetoyloxy)benzoic acid ; _chemical_name_common Aspirin _chemical_formula_sum 'C9 H8 O4' _chemical_formula_weight 180.16 loop_ _atom_type_symbol _atom_type_description _atom_type_scat_length_neutron _atom_type_scat_source 'C' 'C' 6.646 'International Tables Vol C Table 4.4.4.1' 'H' 'H' -3.739 'International Tables Vol C Table 4.4.4.1' 'O' 'O' 5.803 'International Tables Vol C Table 4.4.4.1' _symmetry_cell_setting Monoclinic _symmetry_space_group_name_H-M 'P21/c' loop_ _symmetry_equiv_pos_as_xyz 'x, y, z' '-x, y+1/2, -z+1/2' '-x, -y, -z' 'x, -y-1/2, z-1/2' _cell_length_a 11.233(3) _cell_length_b 6.5440(10) _cell_length_c 11.231(3) _cell_angle_alpha 90.00 _cell_angle_beta 95.89(2) _cell_angle_gamma 90.00 _cell_volume 821.2(3) _cell_formula_units_Z 4 _cell_measurement_temperature 100(1) _cell_measurement_reflns_used 25 _cell_measurement_theta_min ? _cell_measurement_theta_min ? _exptl_crystal_description 'irregular prism' _exptl_crystal_colour colourless _exptl_crystal_size_max 8 _exptl_crystal_size_mid 4 _exptl_crystal_size_min 1.5 _exptl_crystal_density_meas ? _exptl_crystal_density_diffrn 1.456 _exptl_crystal_density_method 'not measured' _exptl_crystal_F_000 21 _exptl_absorpt_coefficient_mu '1.0550, at 1 Angstrom' _exptl_absorpt_correction_type empirical _exptl_absorpt_correction_T_min 0.45 _exptl_absorpt_correction_T_max 0.75 _exptl_absorpt_process_details ; The linear absorption coefficient is wavelength dependent and it is calculated as: mu = 0.80 + 0.75 * lambda [cm^-1] ; _exptl_special_details ; For peak integration a local UB matrix refined for each frame, using approximately 25 reflections. Hence _cell_measurement_reflns_used 25 For final cell dimensions an average of all local cells was performed and estimated standard uncertainties were obtained from the spread of the local observations Because of the nature of the experiment, it is not possible to give values of theta_min and theta_max for the cell determination. Instead, we can give values of #_cell_measurement_sin(theta)/lambda_min 0.20 #_cell_measurement_sin(theta)/lambda_max 0.75 The same applies for the wavelength used for the experiment. The range of wavelengths used was 0.5-5.0 Angstroms, BUT the bulk of the diffraction information is obtained from wavelengths in the range 0.7-2.5 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 0.5-5.0 _diffrn_radiation_type neutron _diffrn_radiation_source 'ISIS spallation source' _diffrn_measurement_device SXD _diffrn_measurement_method 'time-of-flight LAUE diffraction' _diffrn_reflns_number 877 _diffrn_reflns_av_R_equivalents 0.078 _diffrn_reflns_av_sigmaI/netI 0.0391 _diffrn_reflns_limit_h_min 0 _diffrn_reflns_limit_h_max 32 _diffrn_reflns_limit_k_min 0 _diffrn_reflns_limit_k_max 13 _diffrn_reflns_limit_l_min -14 _diffrn_reflns_limit_l_max 16 _diffrn_reflns_theta_min ? _diffrn_reflns_theta_max ? _reflns_number_total 877 _reflns_number_gt 877 _reflns_threshold_expression >2sigma(I) _computing_data_collection ? _computing_cell_refinement ? _computing_data_reduction ? _computing_structure_solution ? _computing_structure_refinement 'SHELXL-97 (Sheldrick, 1997)' _computing_molecular_graphics 'ORTEP (Johnson, 1994)' _computing_publication_material ? _refine_special_details ; These data are by no means complete. They were collected in a very restricted geometry due to the microwave apparatus also installed at the time. The data/parameter ratio is also rather small, however the refinements are stable and supportive of the observations presented in the paper. The microwave source was switched OFF for these data. 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 It is also difficult to estimate realistic values of maximum sin(theta)/lambda values for two reasons: (i) Different sin(theta)/lambda ranges are accessed in different parts of the detectors (ii) The nature of the data collection occasionally allows some reflections at very high sin(theta)/lambda to be observed even when no real attempt has been made to measure data in this region. However, we can attempt to estimate the sin(theta)/lambda limits as follows: #_diffrn_reflns_sin(theta)/lambda_min 0.05 #_diffrn_reflns_sin(theta)/lambda_max 0.65 Note also that reflections for which the standard profile fitting integration procedure fails are excluded from the data set, thus resulting in a high elimination rate of weak or "unobserved" peaks from the final data set. The extinction coefficient reported in _refine_ls_extinction_coef is in this case the refined value of the mosaic spread in units of 10^-4 rad^-1 The reference for the extinction method used is: Becker, P. & Coppens, P. (1974). Acta Cryst. A30, 129-148. 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_structure_factor_coef Fsqd _refine_ls_matrix_type full _refine_ls_weighting_scheme calc _refine_ls_weighting_details 'calc w=1/[\s^2^(Fo^2^)+(0.0763P)^2^+0.3996P] where P=(Fo^2^+2Fc^2^)/3' _refine_ls_hydrogen_treatment refall _refine_ls_extinction_method 'Becker-Coppens Lorentzian model' _refine_ls_extinction_coef 0.06 _refine_ls_number_reflns 877 _refine_ls_number_parameters 190 _refine_ls_number_restraints 0 _refine_ls_R_factor_all 0.0954 _refine_ls_R_factor_gt 0.0954 _refine_ls_wR_factor_ref 0.2433 _refine_ls_wR_factor_gt 0.2433 _refine_ls_goodness_of_fit_ref 1.424 _refine_ls_restrained_S_all 1.424 _refine_ls_shift/su_max 0.000 _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 0.1535(5) 0.5619(8) 0.0664(9) 0.0206(18) Uani 1 1 d . . . C2 C 0.2459(5) 0.4861(9) 0.0092(8) 0.0207(18) Uani 1 1 d . . . C3 C 0.2997(6) 0.3013(10) 0.0406(10) 0.029(2) Uani 1 1 d . . . C4 C 0.2608(6) 0.1908(10) 0.1345(10) 0.030(2) Uani 1 1 d . . . C5 C 0.1692(6) 0.2648(11) 0.1932(9) 0.029(2) Uani 1 1 d . . . C6 C 0.1168(5) 0.4475(9) 0.1604(9) 0.025(2) Uani 1 1 d . . . C7 C 0.0903(5) 0.7572(8) 0.0367(8) 0.0209(19) Uani 1 1 d . . . C8 C 0.3666(5) 0.7380(10) -0.0634(8) 0.0222(17) Uani 1 1 d . . . C9 C 0.3987(7) 0.8386(14) -0.1756(11) 0.033(2) Uani 1 1 d . . . O1 O 0.1216(7) 0.8593(13) -0.0510(11) 0.029(2) Uani 1 1 d . . . O2 O 0.0093(7) 0.8120(12) 0.0960(12) 0.033(3) Uani 1 1 d . . . O3 O 0.2866(6) 0.5846(11) -0.0881(10) 0.0220(19) Uani 1 1 d . . . O4 O 0.4034(8) 0.7810(16) 0.0358(12) 0.039(3) Uani 1 1 d . . . H1 H 0.3689(15) 0.241(2) -0.009(2) 0.046(5) Uani 1 1 d . . . H2 H 0.3017(16) 0.044(2) 0.158(2) 0.050(6) Uani 1 1 d . . . H3 H 0.1401(17) 0.177(3) 0.270(2) 0.046(5) Uani 1 1 d . . . H4 H 0.0444(13) 0.508(3) 0.206(2) 0.043(5) Uani 1 1 d . . . H5 H 0.463(3) 0.954(4) -0.145(3) 0.073(8) Uani 1 1 d . . . H6 H 0.323(3) 0.902(9) -0.220(5) 0.16(3) Uani 1 1 d . . . H7 H 0.429(5) 0.738(5) -0.240(4) 0.120(16) Uani 1 1 d . . . H8 H 0.0702(14) 0.984(3) -0.067(2) 0.049(6) 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 0.018(2) 0.018(2) 0.025(5) 0.004(3) 0.000(3) 0.0010(16) C2 0.021(2) 0.022(2) 0.021(6) -0.005(3) 0.008(3) 0.0003(18) C3 0.027(3) 0.023(3) 0.036(6) 0.005(3) 0.003(4) 0.0057(19) C4 0.031(3) 0.023(3) 0.036(7) 0.000(3) 0.006(4) 0.005(2) C5 0.027(3) 0.030(3) 0.030(6) 0.003(3) 0.008(4) 0.000(2) C6 0.022(2) 0.025(3) 0.031(7) 0.000(3) 0.009(4) 0.003(2) C7 0.021(2) 0.018(2) 0.025(6) 0.004(3) 0.008(3) 0.0019(18) C8 0.018(2) 0.031(3) 0.019(5) -0.003(3) 0.005(3) -0.0037(19) C9 0.035(3) 0.048(4) 0.016(6) 0.003(4) 0.005(4) -0.013(3) O1 0.027(3) 0.035(4) 0.027(7) 0.011(4) 0.012(4) 0.011(3) O2 0.035(3) 0.027(3) 0.040(8) 0.011(4) 0.019(5) 0.013(3) O3 0.025(3) 0.027(3) 0.017(6) -0.006(3) 0.012(4) -0.003(2) O4 0.034(4) 0.056(6) 0.027(7) -0.006(5) 0.006(5) -0.022(4) H1 0.046(7) 0.044(8) 0.051(16) 0.001(8) 0.010(10) 0.012(6) H2 0.059(9) 0.029(6) 0.062(18) 0.004(8) 0.012(11) 0.019(6) H3 0.061(9) 0.044(8) 0.036(15) 0.016(8) 0.013(11) -0.002(6) H4 0.037(6) 0.051(8) 0.042(15) 0.011(8) 0.007(8) 0.009(6) H5 0.100(16) 0.075(13) 0.04(2) -0.002(11) 0.007(16) -0.048(12) H6 0.062(14) 0.25(5) 0.17(5) 0.18(5) 0.00(2) -0.01(2) H7 0.24(5) 0.064(16) 0.07(3) 0.004(16) 0.07(3) 0.00(2) H8 0.046(7) 0.041(7) 0.060(19) 0.009(8) 0.010(10) 0.011(6) _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 _geom_bond_site_symmetry_2 _geom_bond_publ_flag C1 C2 1.368(10) . ? C1 C6 1.391(13) . ? C1 C7 1.483(8) . ? C2 C3 1.381(9) . ? C2 O3 1.386(13) . ? C3 C4 1.386(14) . ? C3 H1 1.08(2) . ? C4 C5 1.367(12) . ? C4 H2 1.088(15) . ? C5 C6 1.367(10) . ? C5 H3 1.11(2) . ? C6 H4 1.08(2) . ? C7 O2 1.234(12) . ? C7 O1 1.270(14) . ? C8 O4 1.182(15) . ? C8 O3 1.357(9) . ? C8 C9 1.498(15) . ? C9 H5 1.07(2) . ? C9 H6 1.03(3) . ? C9 H7 1.06(5) . ? O1 H8 1.006(17) . ? 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 117.4(6) . . ? C2 C1 C7 125.2(7) . . ? C6 C1 C7 117.5(6) . . ? C1 C2 C3 122.0(8) . . ? C1 C2 O3 121.9(6) . . ? C3 C2 O3 115.9(7) . . ? C2 C3 C4 119.2(8) . . ? C2 C3 H1 120.6(13) . . ? C4 C3 H1 120.2(12) . . ? C5 C4 C3 119.6(6) . . ? C5 C4 H2 121.1(16) . . ? C3 C4 H2 119.2(16) . . ? C6 C5 C4 120.3(9) . . ? C6 C5 H3 120.6(12) . . ? C4 C5 H3 119.0(12) . . ? C5 C6 C1 121.5(7) . . ? C5 C6 H4 121.3(12) . . ? C1 C6 H4 117.2(11) . . ? O2 C7 O1 122.9(7) . . ? O2 C7 C1 119.5(7) . . ? O1 C7 C1 117.6(7) . . ? O4 C8 O3 121.9(9) . . ? O4 C8 C9 126.7(7) . . ? O3 C8 C9 111.4(8) . . ? C8 C9 H5 105(2) . . ? C8 C9 H6 109(2) . . ? H5 C9 H6 111(4) . . ? C8 C9 H7 115(2) . . ? H5 C9 H7 114(3) . . ? H6 C9 H7 103(5) . . ? C7 O1 H8 111.3(18) . . ? C8 O3 C2 116.6(8) . . ? _refine_diff_density_max 0.126 _refine_diff_density_min -0.146 _refine_diff_density_rms 0.031 data_asp300 _database_code_CSD 185475 _audit_creation_method SHELXL-97 _chemical_name_systematic ; 2-(acetoyloxy)benzoic acid ; _chemical_name_common Aspirin _chemical_formula_sum 'C9 H8 O4' _chemical_formula_weight 180.16 loop_ _atom_type_symbol _atom_type_description _atom_type_scat_length_neutron _atom_type_scat_source 'C' 'C' 6.646 'International Tables Vol C Table 4.4.4.1' 'H' 'H' -3.739 'International Tables Vol C Table 4.4.4.1' 'O' 'O' 5.803 'International Tables Vol C Table 4.4.4.1' _symmetry_cell_setting Monoclinic _symmetry_space_group_name_H-M 'P21/c' loop_ _symmetry_equiv_pos_as_xyz 'x, y, z' '-x, y+1/2, -z+1/2' '-x, -y, -z' 'x, -y-1/2, z-1/2' _cell_length_a 11.233(3) _cell_length_b 6.5440(10) _cell_length_c 11.231(3) _cell_angle_alpha 90.00 _cell_angle_beta 95.89(2) _cell_angle_gamma 90.00 _cell_volume 821.2(3) _cell_formula_units_Z 4 _cell_measurement_temperature 100(1) _cell_measurement_reflns_used 25 _cell_measurement_theta_min ? _cell_measurement_theta_min ? _exptl_crystal_description 'irregular prism' _exptl_crystal_colour colourless _exptl_crystal_size_max 8 _exptl_crystal_size_mid 4 _exptl_crystal_size_min 1.5 _exptl_crystal_density_meas ? _exptl_crystal_density_diffrn 1.456 _exptl_crystal_density_method 'not measured' _exptl_crystal_F_000 21 _exptl_absorpt_coefficient_mu '1.0550, at 1 Angstrom' _exptl_absorpt_correction_type empirical _exptl_absorpt_correction_T_min 0.45 _exptl_absorpt_correction_T_max 0.75 _exptl_absorpt_process_details ; The linear absorption coefficient is wavelength dependent and it is calculated as: mu = 0.80 + 0.75 * lambda [cm^-1] ; _exptl_special_details ; For peak integration a local UB matrix refined for each frame, using approximately 25 reflections. Hence _cell_measurement_reflns_used 25 For final cell dimensions an average of all local cells was performed and estimated standard uncertainties were obtained from the spread of the local observations Because of the nature of the experiment, it is not possible to give values of theta_min and theta_max for the cell determination. Instead, we can give values of #_cell_measurement_sin(theta)/lambda_min 0.20 #_cell_measurement_sin(theta)/lambda_max 0.75 The same applies for the wavelength used for the experiment. The range of wavelengths used was 0.5-5.0 Angstroms, BUT the bulk of the diffraction information is obtained from wavelengths in the range 0.7-2.5 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 0.5-5.0 _diffrn_radiation_type neutron _diffrn_radiation_source ISIS spallation source _diffrn_measurement_device SXD _diffrn_measurement_method 'time-of-flight LAUE diffraction' _diffrn_reflns_number 2794 _diffrn_reflns_av_R_equivalents 0.085 _diffrn_reflns_av_sigmaI/netI 0.0379 _diffrn_reflns_limit_h_min 0 _diffrn_reflns_limit_h_max 21 _diffrn_reflns_limit_k_min 0 _diffrn_reflns_limit_k_max 15 _diffrn_reflns_limit_l_min -14 _diffrn_reflns_limit_l_max 15 _diffrn_reflns_theta_min ? _diffrn_reflns_theta_max ? _reflns_number_total 625 _reflns_number_gt 625 _reflns_threshold_expression >2sigma(I) _computing_data_collection ? _computing_cell_refinement ? _computing_data_reduction ? _computing_structure_solution ? _computing_structure_refinement 'SHELXL-97 (Sheldrick, 1997)' _computing_molecular_graphics 'ORTEP (Johnson, 1994)' _computing_publication_material ? _refine_special_details ; These data are by no means complete. They were collected in a very restricted geometry due to the microwave apparatus also installed at the time. The data/parameter ratio is also rather small, however the refinements are stable and supportive of the observations presented in the paper. The microwave source was switched OFF for these data. 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 It is also difficult to estimate realistic values of maximum sin(theta)/lambda values for two reasons: (i) Different sin(theta)/lambda ranges are accessed in different parts of the detectors (ii) The nature of the data collection occasionally allows some reflections at very high sin(theta)/lambda to be observed even when no real attempt has been made to measure data in this region. However, we can attempt to estimate the sin(theta)/lambda limits as follows: #_diffrn_reflns_sin(theta)/lambda_min 0.05 #_diffrn_reflns_sin(theta)/lambda_max 0.55 Note also that reflections for which the standard profile fitting integration procedure fails are excluded from the data set, thus resulting in a high elimination rate of weak or "unobserved" peaks from the final data set. The extinction coefficient reported in _refine_ls_extinction_coef is in this case the refined value of the mosaic spread in units of 10^-4 rad^-1 The reference for the extinction method used is: Becker, P. & Coppens, P. (1974). Acta Cryst. A30, 129-148. 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_structure_factor_coef Fsqd _refine_ls_matrix_type full _refine_ls_weighting_scheme calc _refine_ls_weighting_details 'calc w=1/[\s^2^(Fo^2^)+(0.0763P)^2^+0.3996P] where P=(Fo^2^+2Fc^2^)/3' _refine_ls_hydrogen_treatment refall _refine_ls_extinction_method Becker-Coppens Lorentzian model _refine_ls_extinction_coef 0.06 _refine_ls_number_reflns 625 _refine_ls_number_parameters 155 _refine_ls_number_restraints 0 _refine_ls_R_factor_all 0.1127 _refine_ls_R_factor_gt 0.1127 _refine_ls_wR_factor_ref 0.2678 _refine_ls_wR_factor_gt 0.2678 _refine_ls_goodness_of_fit_ref 1.452 _refine_ls_restrained_S_all 1.452 _refine_ls_shift/su_max 0.000 _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 0.1536(7) 0.5626(14) 0.0664(12) 0.031(3) Uani 1 1 d . . . C2 C 0.2446(7) 0.4882(13) 0.0101(13) 0.036(4) Uani 1 1 d . . . C3 C 0.2993(9) 0.3040(15) 0.0427(16) 0.046(4) Uani 1 1 d . . . C4 C 0.2611(9) 0.1928(15) 0.1356(16) 0.046(4) Uani 1 1 d . . . C5 C 0.1685(8) 0.2675(14) 0.1950(15) 0.044(4) Uani 1 1 d . . . C6 C 0.1162(8) 0.4490(15) 0.1624(14) 0.042(4) Uani 1 1 d . . . C7 C 0.0901(7) 0.7581(13) 0.0365(14) 0.036(3) Uani 1 1 d . . . C8 C 0.3652(8) 0.7384(15) -0.0633(15) 0.039(3) Uani 1 1 d . . . C9 C 0.3978(11) 0.841(2) -0.1735(15) 0.050(4) Uani 1 1 d . . . O1 O 0.1205(10) 0.864(2) -0.0482(16) 0.042(4) Uani 1 1 d . . . O2 O 0.0084(11) 0.8109(18) 0.0992(18) 0.048(5) Uani 1 1 d . . . O3 O 0.2849(10) 0.5893(18) -0.0869(16) 0.044(4) Uani 1 1 d . . . O4 O 0.4020(12) 0.781(2) 0.0346(18) 0.052(4) Uani 1 1 d . . . H1 H 0.368(2) 0.247(4) -0.002(3) 0.065(6) Uiso 1 1 d . . . H2 H 0.305(2) 0.054(4) 0.157(4) 0.067(7) Uiso 1 1 d . . . H3 H 0.144(2) 0.179(4) 0.267(4) 0.070(7) Uiso 1 1 d . . . H4 H 0.046(2) 0.503(4) 0.202(3) 0.061(6) Uiso 1 1 d . . . H5 H 0.473(3) 0.960(6) -0.147(5) 0.100(11) Uiso 1 1 d . . . H6 H 0.327(8) 0.869(14) -0.231(10) 0.20(3) Uiso 1 1 d . . . H7 H 0.437(5) 0.715(10) -0.269(8) 0.16(2) Uiso 1 1 d . . . H8 H 0.070(3) 0.996(4) -0.071(4) 0.079(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 0.030(3) 0.040(4) 0.024(8) -0.005(5) 0.002(5) 0.001(3) C2 0.031(4) 0.030(4) 0.048(12) -0.003(5) 0.010(6) -0.005(3) C3 0.048(5) 0.038(5) 0.052(12) 0.004(5) -0.002(7) 0.009(4) C4 0.052(5) 0.034(5) 0.053(13) 0.004(5) 0.017(7) 0.008(4) C5 0.041(4) 0.030(4) 0.060(12) 0.015(5) 0.009(6) -0.001(3) C6 0.038(4) 0.041(5) 0.049(12) 0.002(6) 0.011(6) 0.001(4) C7 0.035(4) 0.034(5) 0.041(10) -0.001(5) 0.006(6) 0.003(3) C8 0.028(4) 0.055(6) 0.034(10) -0.009(6) 0.006(5) -0.005(4) C9 0.052(6) 0.074(7) 0.022(10) 0.006(6) 0.002(8) -0.015(5) O1 0.048(6) 0.046(6) 0.038(12) 0.020(7) 0.032(8) 0.017(5) O2 0.052(6) 0.046(6) 0.050(16) 0.007(6) 0.024(8) 0.022(5) O3 0.038(5) 0.049(6) 0.045(13) -0.002(7) 0.002(7) -0.008(4) O4 0.055(6) 0.082(9) 0.019(12) -0.002(7) 0.008(9) -0.029(6) H8 0.092(17) 0.071(15) 0.07(3) 0.001(15) -0.01(2) 0.008(13) _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 _geom_bond_site_symmetry_2 _geom_bond_publ_flag C1 C2 1.346(15) . ? C1 C6 1.409(19) . ? C1 C7 1.487(12) . ? C2 C3 1.385(13) . ? C2 O3 1.39(2) . ? C3 C4 1.38(2) . ? C3 H1 1.03(4) . ? C4 C5 1.38(2) . ? C4 H2 1.05(3) . ? C5 C6 1.359(14) . ? C5 H3 1.06(4) . ? C6 H4 1.01(4) . ? C7 O1 1.25(2) . ? C7 O2 1.261(19) . ? C8 O4 1.17(2) . ? C8 O3 1.336(15) . ? C8 C9 1.49(2) . ? C9 H5 1.17(4) . ? C9 H6 0.99(11) . ? C9 H7 1.46(9) . ? O1 H8 1.05(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 118.0(9) . . ? C2 C1 C7 125.1(11) . . ? C6 C1 C7 117.0(10) . . ? C1 C2 C3 121.9(13) . . ? C1 C2 O3 121.4(10) . . ? C3 C2 O3 116.7(12) . . ? C4 C3 C2 119.7(13) . . ? C4 C3 H1 119.2(19) . . ? C2 C3 H1 121(2) . . ? C3 C4 C5 119.2(10) . . ? C3 C4 H2 117(2) . . ? C5 C4 H2 124(2) . . ? C6 C5 C4 120.4(13) . . ? C6 C5 H3 122.9(19) . . ? C4 C5 H3 116.8(17) . . ? C5 C6 C1 120.8(12) . . ? C5 C6 H4 122(2) . . ? C1 C6 H4 117.2(19) . . ? O1 C7 O2 122.9(11) . . ? O1 C7 C1 119.1(12) . . ? O2 C7 C1 118.0(12) . . ? O4 C8 O3 121.7(16) . . ? O4 C8 C9 125.7(12) . . ? O3 C8 C9 112.6(14) . . ? C8 C9 H5 109(3) . . ? C8 C9 H6 112(6) . . ? H5 C9 H6 124(6) . . ? C8 C9 H7 119(3) . . ? H5 C9 H7 107(4) . . ? H6 C9 H7 85(7) . . ? C7 O1 H8 118(3) . . ? C8 O3 C2 117.4(15) . . ? _refine_diff_density_max 0.112 _refine_diff_density_min -0.094 _refine_diff_density_rms 0.025