Supplementary Material (ESI) for Chemical Communications This journal is (c) The Royal Society of Chemistry 2010 data_global _journal_name_full Chem.Commun. _journal_coden_Cambridge 0182 _publ_contact_author_name 'Qian Miao' _publ_contact_author_email MIAOQIAN@CUHK.EDU.HK _publ_section_title ; N-Heteroquinones: Quadruple Weak Hydrogen Bonds and N-Channel Transistors ; _publ_author_name 'Qian Miao' # Attachment 'DATQ-CC.cif' data_DATQ _database_code_depnum_ccdc_archive 'CCDC 761662' #TrackingRef 'DATQ-CC.cif' _audit_creation_method SHELXL-97 _chemical_name_systematic ; ? ; _chemical_name_common ? _chemical_melting_point ? _chemical_formula_moiety ? _chemical_formula_sum 'C16 H8 N2 O2' _chemical_formula_weight 260.24 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 0.0000 0.0000 'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4' N N 0.0061 0.0033 'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4' O O 0.0106 0.0060 'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4' _symmetry_cell_setting Monoclinic _symmetry_space_group_name_H-M P2(1)/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 12.1301(6) _cell_length_b 3.8545(2) _cell_length_c 24.3276(12) _cell_angle_alpha 90.00 _cell_angle_beta 94.5780(10) _cell_angle_gamma 90.00 _cell_volume 1133.82(10) _cell_formula_units_Z 4 _cell_measurement_temperature 296(2) _cell_measurement_reflns_used 70 _cell_measurement_theta_min 15 _cell_measurement_theta_max 15 _exptl_crystal_description block _exptl_crystal_colour yellow _exptl_crystal_size_max 0.40 _exptl_crystal_size_mid 0.30 _exptl_crystal_size_min 0.20 _exptl_crystal_density_meas ? _exptl_crystal_density_diffrn 1.525 _exptl_crystal_density_method 'not measured' _exptl_crystal_F_000 536 _exptl_absorpt_coefficient_mu 0.103 _exptl_absorpt_correction_type multi-scan _exptl_absorpt_correction_T_min 0.6214 _exptl_absorpt_correction_T_max 0.7456 _exptl_absorpt_process_details ? _exptl_special_details ; ? ; _diffrn_ambient_temperature 296(2) _diffrn_radiation_wavelength 0.71073 _diffrn_radiation_type MoK\a _diffrn_radiation_source 'fine-focus sealed tube' _diffrn_radiation_monochromator graphite _diffrn_measurement_device_type 'BRUKER KAPPA APEXII DUO DIFFRACTOMETER' _diffrn_measurement_method 'PHI & OMEGA SCAN' _diffrn_detector_area_resol_mean ? _diffrn_reflns_number 12534 _diffrn_reflns_av_R_equivalents 0.0378 _diffrn_reflns_av_sigmaI/netI 0.0236 _diffrn_reflns_limit_h_min -14 _diffrn_reflns_limit_h_max 14 _diffrn_reflns_limit_k_min -2 _diffrn_reflns_limit_k_max 4 _diffrn_reflns_limit_l_min -29 _diffrn_reflns_limit_l_max 29 _diffrn_reflns_theta_min 1.68 _diffrn_reflns_theta_max 25.25 _reflns_number_total 2067 _reflns_number_gt 1568 _reflns_threshold_expression >2sigma(I) _computing_data_collection 'BRUKER KAPPA APEXII DUO DIFFRACTOMETER' _computing_cell_refinement 'BRUKER KAPPA APEXII DUO DIFFRACTOMETER' _computing_data_reduction 'BRUKER KAPPA APEXII DUO DIFFRACTOMETER' _computing_structure_solution 'SHELXS-97 (Sheldrick, 2008)' _computing_structure_refinement 'SHELXL-97 (Sheldrick, 2008)' _computing_molecular_graphics 'SIEMENS SHELXTL' _computing_publication_material 'SIEMENS SHELXTL' _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^ > 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^)+(0.0594P)^2^+0.3153P] where P=(Fo^2^+2Fc^2^)/3' _atom_sites_solution_primary direct _atom_sites_solution_secondary difmap _atom_sites_solution_hydrogens geom _refine_ls_hydrogen_treatment riding _refine_ls_extinction_method none _refine_ls_extinction_coef ? _refine_ls_number_reflns 2067 _refine_ls_number_parameters 181 _refine_ls_number_restraints 0 _refine_ls_R_factor_all 0.0564 _refine_ls_R_factor_gt 0.0388 _refine_ls_wR_factor_ref 0.1315 _refine_ls_wR_factor_gt 0.1119 _refine_ls_goodness_of_fit_ref 1.172 _refine_ls_restrained_S_all 1.172 _refine_ls_shift/su_max 0.002 _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 N1 N 0.13356(11) 0.0851(4) 0.44865(6) 0.0364(4) Uani 1 1 d . . . N2 N 0.36287(11) 0.2166(4) 0.45118(6) 0.0363(4) Uani 1 1 d . . . C1 C 0.19255(13) 0.0018(4) 0.40735(7) 0.0325(4) Uani 1 1 d . . . C2 C 0.13143(13) -0.1536(5) 0.35740(7) 0.0380(4) Uani 1 1 d . . . C3 C 0.19718(13) -0.2686(4) 0.31183(7) 0.0332(4) Uani 1 1 d . . . C4 C 0.14307(15) -0.4204(5) 0.26535(8) 0.0405(5) Uani 1 1 d . . . H4A H 0.0668 -0.4498 0.2634 0.049 Uiso 1 1 calc R . . C5 C 0.20187(16) -0.5279(5) 0.22205(8) 0.0440(5) Uani 1 1 d . . . H5A H 0.1650 -0.6255 0.1908 0.053 Uiso 1 1 calc R . . C6 C 0.31555(16) -0.4903(5) 0.22518(8) 0.0438(5) Uani 1 1 d . . . H6A H 0.3552 -0.5676 0.1964 0.053 Uiso 1 1 calc R . . C7 C 0.37025(15) -0.3384(5) 0.27088(7) 0.0396(4) Uani 1 1 d . . . H7A H 0.4467 -0.3122 0.2725 0.048 Uiso 1 1 calc R . . C8 C 0.31224(13) -0.2238(4) 0.31457(7) 0.0331(4) Uani 1 1 d . . . C9 C 0.37319(13) -0.0480(5) 0.36209(7) 0.0356(4) Uani 1 1 d . . . C10 C 0.30812(13) 0.0624(5) 0.40901(7) 0.0322(4) Uani 1 1 d . . . C11 C 0.18813(13) 0.2365(5) 0.49308(7) 0.0336(4) Uani 1 1 d . . . C12 C 0.13001(15) 0.3310(5) 0.53879(7) 0.0404(5) Uani 1 1 d . . . H12A H 0.0550 0.2819 0.5390 0.048 Uiso 1 1 calc R . . C13 C 0.18397(16) 0.4936(5) 0.58245(7) 0.0435(5) Uani 1 1 d . . . H13A H 0.1452 0.5592 0.6122 0.052 Uiso 1 1 calc R . . C14 C 0.29816(16) 0.5646(5) 0.58327(8) 0.0466(5) Uani 1 1 d . . . H14A H 0.3335 0.6751 0.6138 0.056 Uiso 1 1 calc R . . C15 C 0.35739(15) 0.4747(5) 0.54045(7) 0.0435(5) Uani 1 1 d . . . H15A H 0.4327 0.5228 0.5417 0.052 Uiso 1 1 calc R . . C16 C 0.30409(14) 0.3080(5) 0.49413(7) 0.0343(4) Uani 1 1 d . . . O1 O 0.03165(10) -0.1836(5) 0.35431(6) 0.0667(5) Uani 1 1 d . . . O2 O 0.47159(10) 0.0073(4) 0.36296(6) 0.0570(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 N1 0.0288(7) 0.0440(9) 0.0363(8) 0.0009(7) 0.0017(6) -0.0032(6) N2 0.0294(7) 0.0432(9) 0.0362(8) 0.0015(7) 0.0017(6) -0.0056(6) C1 0.0284(8) 0.0353(10) 0.0338(9) 0.0052(8) 0.0027(7) -0.0015(7) C2 0.0278(8) 0.0474(11) 0.0384(10) 0.0004(8) 0.0007(7) -0.0045(8) C3 0.0336(9) 0.0313(9) 0.0343(9) 0.0043(7) -0.0012(7) -0.0006(7) C4 0.0362(9) 0.0419(11) 0.0421(10) 0.0007(9) -0.0050(8) -0.0011(8) C5 0.0514(11) 0.0426(11) 0.0365(10) -0.0030(8) -0.0053(8) 0.0026(9) C6 0.0534(11) 0.0421(11) 0.0364(10) 0.0016(9) 0.0077(8) 0.0053(9) C7 0.0384(9) 0.0418(11) 0.0390(10) 0.0025(8) 0.0055(8) 0.0003(8) C8 0.0335(8) 0.0316(9) 0.0342(9) 0.0057(7) 0.0035(7) -0.0001(7) C9 0.0293(8) 0.0393(10) 0.0383(9) 0.0040(8) 0.0036(7) -0.0034(7) C10 0.0285(8) 0.0346(10) 0.0332(9) 0.0049(7) 0.0005(7) -0.0026(7) C11 0.0321(9) 0.0347(10) 0.0341(9) 0.0045(8) 0.0022(7) -0.0025(7) C12 0.0365(9) 0.0459(11) 0.0393(10) 0.0022(9) 0.0065(8) -0.0030(8) C13 0.0511(11) 0.0449(12) 0.0357(9) -0.0002(9) 0.0104(8) -0.0017(9) C14 0.0537(11) 0.0494(12) 0.0362(10) -0.0031(9) 0.0014(8) -0.0125(9) C15 0.0373(9) 0.0516(12) 0.0412(10) -0.0020(9) 0.0007(8) -0.0103(9) C16 0.0337(9) 0.0352(10) 0.0339(9) 0.0048(8) 0.0028(7) -0.0040(7) O1 0.0302(7) 0.1156(14) 0.0541(9) -0.0239(9) 0.0016(6) -0.0112(8) O2 0.0298(7) 0.0885(12) 0.0535(8) -0.0153(8) 0.0087(6) -0.0121(7) _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 N1 C1 1.319(2) . ? N1 C11 1.354(2) . ? N2 C10 1.318(2) . ? N2 C16 1.358(2) . ? C1 C10 1.419(2) . ? C1 C2 1.497(2) . ? C2 O1 1.212(2) . ? C2 C3 1.484(2) . ? C3 C4 1.391(2) . ? C3 C8 1.403(2) . ? C4 C5 1.382(3) . ? C5 C6 1.383(3) . ? C6 C7 1.379(3) . ? C7 C8 1.393(2) . ? C8 C9 1.485(2) . ? C9 O2 1.211(2) . ? C9 C10 1.500(2) . ? C11 C12 1.411(2) . ? C11 C16 1.432(2) . ? C12 C13 1.356(3) . ? C13 C14 1.411(3) . ? C14 C15 1.357(3) . ? C15 C16 1.409(2) . ? 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 C1 N1 C11 116.92(14) . . ? C10 N2 C16 116.94(14) . . ? N1 C1 C10 122.22(16) . . ? N1 C1 C2 116.88(14) . . ? C10 C1 C2 120.88(15) . . ? O1 C2 C3 121.24(16) . . ? O1 C2 C1 121.06(16) . . ? C3 C2 C1 117.71(14) . . ? C4 C3 C8 119.60(16) . . ? C4 C3 C2 119.09(15) . . ? C8 C3 C2 121.31(15) . . ? C5 C4 C3 120.47(17) . . ? C4 C5 C6 119.99(17) . . ? C7 C6 C5 120.17(17) . . ? C6 C7 C8 120.67(17) . . ? C7 C8 C3 119.08(16) . . ? C7 C8 C9 119.23(15) . . ? C3 C8 C9 121.67(15) . . ? O2 C9 C8 121.52(16) . . ? O2 C9 C10 120.96(16) . . ? C8 C9 C10 117.52(14) . . ? N2 C10 C1 122.12(15) . . ? N2 C10 C9 117.19(14) . . ? C1 C10 C9 120.69(15) . . ? N1 C11 C12 119.81(15) . . ? N1 C11 C16 120.95(15) . . ? C12 C11 C16 119.22(16) . . ? C13 C12 C11 119.76(17) . . ? C12 C13 C14 120.85(17) . . ? C15 C14 C13 121.28(18) . . ? C14 C15 C16 119.56(17) . . ? N2 C16 C15 119.89(15) . . ? N2 C16 C11 120.79(15) . . ? C15 C16 C11 119.32(16) . . ? _diffrn_measured_fraction_theta_max 0.999 _diffrn_reflns_theta_full 25.25 _diffrn_measured_fraction_theta_full 0.999 _refine_diff_density_max 0.156 _refine_diff_density_min -0.214 _refine_diff_density_rms 0.045 # Attachment 'TAPQ-CC.cif' data_TAPQ _database_code_depnum_ccdc_archive 'CCDC 761663' #TrackingRef 'TAPQ-CC.cif' _audit_creation_method SHELXL-97 _chemical_name_systematic ; ? ; _chemical_name_common ? _chemical_melting_point ? _chemical_formula_moiety ? _chemical_formula_sum 'C18 H8 N4 O2' _chemical_formula_weight 312.28 loop_ _atom_type_symbol _atom_type_description _atom_type_scat_dispersion_real _atom_type_scat_dispersion_imag _atom_type_scat_source C C 0.0181 0.0091 'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4' H H 0.0000 0.0000 'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4' N N 0.0311 0.0180 'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4' O O 0.0492 0.0322 'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4' _symmetry_cell_setting Monoclinic _symmetry_space_group_name_H-M P2(1)/n 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 3.8926(2) _cell_length_b 9.0707(4) _cell_length_c 18.4339(10) _cell_angle_alpha 90.00 _cell_angle_beta 92.332(4) _cell_angle_gamma 90.00 _cell_volume 650.34(6) _cell_formula_units_Z 2 _cell_measurement_temperature 296(2) _cell_measurement_reflns_used 71 _cell_measurement_theta_min 45 _cell_measurement_theta_max 45 _exptl_crystal_description block _exptl_crystal_colour yellow _exptl_crystal_size_max 0.40 _exptl_crystal_size_mid 0.30 _exptl_crystal_size_min 0.20 _exptl_crystal_density_meas ? _exptl_crystal_density_diffrn 1.595 _exptl_crystal_density_method 'not measured' _exptl_crystal_F_000 320 _exptl_absorpt_coefficient_mu 0.899 _exptl_absorpt_correction_type multi-scan _exptl_absorpt_correction_T_min 0.3044 _exptl_absorpt_correction_T_max 0.7529 _exptl_absorpt_process_details ? _exptl_special_details ; ? ; _diffrn_ambient_temperature 296(2) _diffrn_radiation_wavelength 1.54178 _diffrn_radiation_type CuK\a _diffrn_radiation_source 'fine-focus sealed tube' _diffrn_radiation_monochromator graphite _diffrn_measurement_device_type 'BRUKER APEXII DUO DIFFRACTOMETER' _diffrn_measurement_method 'PHI & OMEGA SCAN' _diffrn_detector_area_resol_mean ? _diffrn_reflns_number 3495 _diffrn_reflns_av_R_equivalents 0.0220 _diffrn_reflns_av_sigmaI/netI 0.0212 _diffrn_reflns_limit_h_min -1 _diffrn_reflns_limit_h_max 4 _diffrn_reflns_limit_k_min -10 _diffrn_reflns_limit_k_max 10 _diffrn_reflns_limit_l_min -21 _diffrn_reflns_limit_l_max 21 _diffrn_reflns_theta_min 4.80 _diffrn_reflns_theta_max 67.12 _reflns_number_total 1088 _reflns_number_gt 896 _reflns_threshold_expression >2sigma(I) _computing_data_collection 'BRUKER APEXII DUO DIFFRACTOMETER' _computing_cell_refinement 'BRUKER APEXII DUO DIFFRACTOMETER' _computing_data_reduction 'BRUKER APEXII DUO DIFFRACTOMETER' _computing_structure_solution 'SHELXS-97 (Sheldrick, 2008)' _computing_structure_refinement 'SHELXL-97 (Sheldrick, 2008)' _computing_molecular_graphics 'SIEMENS SHELXTL' _computing_publication_material 'SIEMENS SHELXTL' _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^ > 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^)+(0.1139P)^2^+0.0314P] where P=(Fo^2^+2Fc^2^)/3' _atom_sites_solution_primary direct _atom_sites_solution_secondary difmap _atom_sites_solution_hydrogens geom _refine_ls_hydrogen_treatment riding _refine_ls_extinction_method none _refine_ls_extinction_coef ? _refine_ls_number_reflns 1088 _refine_ls_number_parameters 109 _refine_ls_number_restraints 0 _refine_ls_R_factor_all 0.0561 _refine_ls_R_factor_gt 0.0467 _refine_ls_wR_factor_ref 0.1704 _refine_ls_wR_factor_gt 0.1408 _refine_ls_goodness_of_fit_ref 1.154 _refine_ls_restrained_S_all 1.154 _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 O1 O 0.3700(5) 0.36185(17) 0.39976(8) 0.0663(6) Uani 1 1 d . . . N1 N 0.2220(4) 0.21074(18) 0.52244(8) 0.0438(5) Uani 1 1 d . . . N2 N -0.1233(4) 0.36346(16) 0.63154(9) 0.0445(5) Uani 1 1 d . . . C1 C 0.1958(5) 0.4218(2) 0.44359(10) 0.0448(5) Uani 1 1 d . . . C2 C 0.1154(5) 0.3487(2) 0.51382(10) 0.0410(5) Uani 1 1 d . . . C3 C 0.1561(5) 0.1449(2) 0.58623(10) 0.0421(5) Uani 1 1 d . . . C4 C 0.2546(5) -0.0034(2) 0.59820(11) 0.0484(6) Uani 1 1 d . . . H4A H 0.3598 -0.0564 0.5620 0.058 Uiso 1 1 calc R . . C5 C 0.1941(6) -0.0682(2) 0.66309(11) 0.0514(6) Uani 1 1 d . . . H5A H 0.2577 -0.1659 0.6708 0.062 Uiso 1 1 calc R . . C6 C 0.0367(6) 0.0104(2) 0.71897(11) 0.0518(6) Uani 1 1 d . . . H6A H 0.0028 -0.0358 0.7631 0.062 Uiso 1 1 calc R . . C7 C -0.0659(5) 0.1525(2) 0.70911(11) 0.0477(6) Uani 1 1 d . . . H7A H -0.1702 0.2028 0.7463 0.057 Uiso 1 1 calc R . . C8 C -0.0134(5) 0.2236(2) 0.64207(10) 0.0423(5) Uani 1 1 d . . . C9 C -0.0631(5) 0.4243(2) 0.56832(10) 0.0412(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 O1 0.1012(13) 0.0525(10) 0.0476(10) 0.0049(7) 0.0316(8) 0.0201(7) N1 0.0590(11) 0.0403(9) 0.0322(9) -0.0020(6) 0.0032(6) 0.0016(6) N2 0.0611(11) 0.0413(10) 0.0315(9) -0.0015(6) 0.0056(6) -0.0005(7) C1 0.0605(12) 0.0421(11) 0.0323(11) -0.0039(8) 0.0074(8) 0.0026(8) C2 0.0547(12) 0.0366(10) 0.0319(11) -0.0033(7) 0.0029(8) -0.0005(7) C3 0.0544(12) 0.0408(11) 0.0310(10) -0.0022(7) 0.0003(7) -0.0030(8) C4 0.0634(13) 0.0424(11) 0.0393(11) -0.0024(8) 0.0012(8) 0.0029(8) C5 0.0696(14) 0.0417(10) 0.0427(12) 0.0047(8) -0.0012(9) 0.0015(8) C6 0.0698(14) 0.0503(12) 0.0352(11) 0.0071(8) 0.0012(8) -0.0044(9) C7 0.0634(13) 0.0480(12) 0.0321(10) -0.0007(8) 0.0051(8) -0.0030(8) C8 0.0535(12) 0.0415(10) 0.0317(10) -0.0024(8) 0.0005(7) -0.0033(8) C9 0.0551(12) 0.0403(11) 0.0282(10) -0.0026(7) 0.0033(7) -0.0015(7) _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 O1 C1 1.205(2) . ? N1 C2 1.326(3) . ? N1 C3 1.353(2) . ? N2 C9 1.319(3) . ? N2 C8 1.350(3) . ? C1 C2 1.499(3) . ? C1 C9 1.502(3) 3_566 ? C2 C9 1.421(3) . ? C3 C4 1.413(3) . ? C3 C8 1.436(3) . ? C4 C5 1.362(3) . ? C5 C6 1.413(3) . ? C6 C7 1.359(3) . ? C7 C8 1.416(3) . ? C9 C1 1.502(3) 3_566 ? 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 N1 C3 116.85(16) . . ? C9 N2 C8 116.96(16) . . ? O1 C1 C2 121.49(18) . . ? O1 C1 C9 121.39(18) . 3_566 ? C2 C1 C9 117.07(17) . 3_566 ? N1 C2 C9 122.03(17) . . ? N1 C2 C1 116.47(16) . . ? C9 C2 C1 121.50(18) . . ? N1 C3 C4 119.76(17) . . ? N1 C3 C8 120.82(17) . . ? C4 C3 C8 119.42(18) . . ? C5 C4 C3 119.48(19) . . ? C4 C5 C6 121.25(19) . . ? C7 C6 C5 120.97(18) . . ? C6 C7 C8 119.78(18) . . ? N2 C8 C7 119.84(18) . . ? N2 C8 C3 121.11(17) . . ? C7 C8 C3 119.06(18) . . ? N2 C9 C2 122.18(18) . . ? N2 C9 C1 116.46(17) . 3_566 ? C2 C9 C1 121.36(18) . 3_566 ? _diffrn_measured_fraction_theta_max 0.930 _diffrn_reflns_theta_full 67.12 _diffrn_measured_fraction_theta_full 0.929 _refine_diff_density_max 0.215 _refine_diff_density_min -0.262 _refine_diff_density_rms 0.063