Electronic Supplementary Material for CrystEngComm This Journal is (c) The Royal Society of Chemistry 2007 data_global _journal_name_full CrystEngComm _journal_coden_cambridge 1350 _publ_contact_author ;Prof. A Nangia School of Chemistry University of Hyderabad P O Central University Hyderabad 500046 INDIA ; _publ_contact_author_email 'ASHWINI NANGIA@REDIFFMAIL.COM' _publ_contact_author_name 'Prof. A Nangia' loop_ _publ_author_name A.Nangia 'N. Jagadeesh Babu ' data_pnma _database_code_depnum_ccdc_archive 'CCDC 648204' _audit_creation_method SHELXL-97 _chemical_name_systematic ; Pyrazine-N,N'-dioxide ; _chemical_name_common Pyrazine-N,N'-dioxide _chemical_melting_point '560K (decomp) ' _chemical_formula_moiety ' C2 H2 N O, 0.5(C4 H4 N2 O2)' _chemical_formula_sum 'C4 H4 N2 O2' _chemical_formula_weight 112.09 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 Orthorhombic _symmetry_space_group_name_H-M 'Pnma ' loop_ _symmetry_equiv_pos_as_xyz 'x, y, z' '-x+1/2, -y, z+1/2' '-x, y+1/2, -z' 'x+1/2, -y+1/2, -z+1/2' '-x, -y, -z' 'x-1/2, y, -z-1/2' 'x, -y-1/2, z' '-x-1/2, y-1/2, z-1/2' _cell_length_a 11.8672(18) _cell_length_b 12.2217(19) _cell_length_c 6.4287(10) _cell_angle_alpha 90.00 _cell_angle_beta 90.00 _cell_angle_gamma 90.00 _cell_volume 932.4(2) _cell_formula_units_Z 8 _cell_measurement_temperature 293(2) _cell_measurement_reflns_used 1512 _cell_measurement_theta_min 3.33 _cell_measurement_theta_max 25.94 _exptl_crystal_description plate _exptl_crystal_colour colourless _exptl_crystal_size_max 0.41 _exptl_crystal_size_mid 0.21 _exptl_crystal_size_min 0.06 _exptl_crystal_density_meas ? _exptl_crystal_density_diffrn 1.597 _exptl_crystal_density_method 'not measured' _exptl_crystal_F_000 464 _exptl_absorpt_coefficient_mu 0.131 _exptl_absorpt_correction_type multi-scan _exptl_absorpt_correction_T_min 0.9482 _exptl_absorpt_correction_T_max 0.9922 _exptl_absorpt_process_details 'Bruker AXS SADABS program' _exptl_special_details ; Sheldrick,G.M.,(2003),University of gottingen,Germany ; _diffrn_ambient_temperature 293(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 'CCD area detector' _diffrn_measurement_method 'phi and omega scans' _diffrn_detector_area_resol_mean ? _diffrn_standards_number ? _diffrn_standards_interval_count ? _diffrn_standards_interval_time ? _diffrn_standards_decay_% ? _diffrn_reflns_number 4790 _diffrn_reflns_av_R_equivalents 0.0312 _diffrn_reflns_av_sigmaI/netI 0.0217 _diffrn_reflns_limit_h_min -14 _diffrn_reflns_limit_h_max 12 _diffrn_reflns_limit_k_min -14 _diffrn_reflns_limit_k_max 15 _diffrn_reflns_limit_l_min -6 _diffrn_reflns_limit_l_max 7 _diffrn_reflns_theta_min 3.33 _diffrn_reflns_theta_max 26.01 _reflns_number_total 956 _reflns_number_gt 643 _reflns_threshold_expression >2sigma(I) _computing_data_collection 'Bruker SMART' _computing_cell_refinement 'Bruker SMART' _computing_data_reduction 'Bruker SAINT' _computing_structure_solution 'SHELXS-97 (Sheldrick, 1990)' _computing_structure_refinement 'SHELXL-97 (Sheldrick, 1997)' _computing_molecular_graphics 'Bruker SHELXTL' _computing_publication_material 'Bruker 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^)+(0.0730P)^2^+0.2522P] 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 constr _refine_ls_extinction_method none _refine_ls_extinction_coef ? _refine_ls_number_reflns 956 _refine_ls_number_parameters 85 _refine_ls_number_restraints 0 _refine_ls_R_factor_all 0.0874 _refine_ls_R_factor_gt 0.0605 _refine_ls_wR_factor_ref 0.1584 _refine_ls_wR_factor_gt 0.1439 _refine_ls_goodness_of_fit_ref 1.151 _refine_ls_restrained_S_all 1.151 _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 N2 N 0.5620(2) 0.2500 0.1955(4) 0.0328(7) Uani 1 2 d S . . O2 O 0.4985(2) 0.2500 0.3607(4) 0.0466(7) Uani 1 2 d S . . O1 O 0.7642(2) 0.2500 -0.3092(4) 0.0714(10) Uani 1 2 d S . . C1 C 0.7432(3) 0.2500 0.0447(5) 0.0381(9) Uani 1 2 d S . . H1 H 0.8211 0.2500 0.0613 0.046 Uiso 1 2 calc SR . . C3 C 0.5188(3) 0.2500 0.0012(5) 0.0368(9) Uani 1 2 d S . . H3 H 0.4410 0.2500 -0.0157 0.044 Uiso 1 2 calc SR . . C2 C 0.6762(3) 0.2500 0.2151(5) 0.0369(9) Uani 1 2 d S . . H2 H 0.7085 0.2500 0.3469 0.044 Uiso 1 2 calc SR . . N1 N 0.6989(2) 0.2500 -0.1494(4) 0.0424(8) Uani 1 2 d S . . C4 C 0.5847(3) 0.2500 -0.1677(5) 0.0424(9) Uani 1 2 d S . . H4 H 0.5520 0.2500 -0.2992 0.051 Uiso 1 2 calc SR . . O3 O 0.36647(16) 0.49092(17) 0.1660(3) 0.0577(7) Uani 1 1 d . . . N3 N 0.43087(18) 0.49625(16) 0.3286(3) 0.0365(6) Uani 1 1 d . . . C5 C 0.3878(2) 0.4920(2) 0.5233(4) 0.0378(7) Uani 1 1 d . . . H5 H 0.3103 0.4869 0.5413 0.045 Uiso 1 1 calc R . . C6 C 0.5444(2) 0.50498(19) 0.3080(4) 0.0370(7) Uani 1 1 d . . . H6 H 0.5760 0.5089 0.1758 0.044 Uiso 1 1 calc R . . 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 N2 0.0243(15) 0.0462(17) 0.0279(15) 0.000 0.0006(11) 0.000 O2 0.0301(14) 0.0754(19) 0.0343(13) 0.000 0.0105(10) 0.000 O1 0.0403(17) 0.140(3) 0.0341(16) 0.000 0.0142(12) 0.000 C1 0.0231(18) 0.055(2) 0.036(2) 0.000 -0.0004(14) 0.000 C3 0.0213(17) 0.052(2) 0.0370(19) 0.000 -0.0024(14) 0.000 C2 0.0237(17) 0.054(2) 0.0334(19) 0.000 -0.0026(14) 0.000 N1 0.0313(17) 0.065(2) 0.0307(16) 0.000 0.0012(12) 0.000 C4 0.035(2) 0.061(2) 0.0313(19) 0.000 -0.0070(16) 0.000 O3 0.0364(12) 0.1026(18) 0.0342(11) -0.0040(11) -0.0122(8) -0.0007(10) N3 0.0259(11) 0.0541(14) 0.0296(11) -0.0031(9) -0.0036(8) 0.0006(9) C5 0.0223(12) 0.0509(15) 0.0402(14) -0.0035(12) 0.0028(10) -0.0013(10) C6 0.0268(14) 0.0526(16) 0.0315(13) -0.0011(11) 0.0076(10) -0.0009(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 _geom_bond_site_symmetry_2 _geom_bond_publ_flag N2 O2 1.302(3) . ? N2 C3 1.350(4) . ? N2 C2 1.361(4) . ? O1 N1 1.287(3) . ? C1 C2 1.354(5) . ? C1 N1 1.354(4) . ? C1 H1 0.9300 . ? C3 C4 1.338(5) . ? C3 H3 0.9300 . ? C2 H2 0.9300 . ? N1 C4 1.361(4) . ? C4 H4 0.9300 . ? O3 N3 1.297(2) . ? N3 C5 1.353(3) . ? N3 C6 1.358(3) . ? C5 C6 1.350(4) 5_666 ? C5 H5 0.9300 . ? C6 C5 1.350(4) 5_666 ? C6 H6 0.9300 . ? 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 O2 N2 C3 122.3(3) . . ? O2 N2 C2 120.0(3) . . ? C3 N2 C2 117.6(3) . . ? C2 C1 N1 121.2(3) . . ? C2 C1 H1 119.4 . . ? N1 C1 H1 119.4 . . ? C4 C3 N2 122.0(3) . . ? C4 C3 H3 119.0 . . ? N2 C3 H3 119.0 . . ? C1 C2 N2 120.7(3) . . ? C1 C2 H2 119.7 . . ? N2 C2 H2 119.7 . . ? O1 N1 C1 120.1(3) . . ? O1 N1 C4 122.1(3) . . ? C1 N1 C4 117.8(3) . . ? C3 C4 N1 120.8(3) . . ? C3 C4 H4 119.6 . . ? N1 C4 H4 119.6 . . ? O3 N3 C5 121.4(2) . . ? O3 N3 C6 120.7(2) . . ? C5 N3 C6 117.9(2) . . ? C6 C5 N3 121.2(2) 5_666 . ? C6 C5 H5 119.4 5_666 . ? N3 C5 H5 119.4 . . ? C5 C6 N3 120.9(2) 5_666 . ? C5 C6 H6 119.5 5_666 . ? N3 C6 H6 119.5 . . ? _diffrn_measured_fraction_theta_max 1.000 _diffrn_reflns_theta_full 26.01 _diffrn_measured_fraction_theta_full 1.000 _refine_diff_density_max 0.223 _refine_diff_density_min -0.314 _refine_diff_density_rms 0.060 # Attachment 'form-2.cif' data_an639c_m _database_code_depnum_ccdc_archive 'CCDC 648205' _audit_creation_method SHELXL-97 _chemical_name_systematic ; Pyrazine-N,N'-dioxide ; _chemical_name_common Pyrazine-N,N'-dioxide _chemical_melting_point '557K (decomp) ' _chemical_formula_moiety 'C4 H4 N2 O2' _chemical_formula_sum 'C4 H4 N2 O2' _chemical_formula_weight 112.09 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 'p 2 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 3.7239(13) _cell_length_b 11.010(4) _cell_length_c 5.683(2) _cell_angle_alpha 90.00 _cell_angle_beta 96.237(5) _cell_angle_gamma 90.00 _cell_volume 231.62(14) _cell_formula_units_Z 2 _cell_measurement_temperature 293(2) _cell_measurement_reflns_used 1174 _cell_measurement_theta_min 3.70 _cell_measurement_theta_max 25.91 _exptl_crystal_description plate _exptl_crystal_colour colourless _exptl_crystal_size_max 0.48 _exptl_crystal_size_mid 0.20 _exptl_crystal_size_min 0.02 _exptl_crystal_density_meas ? _exptl_crystal_density_diffrn 1.607 _exptl_crystal_density_method 'not measured' _exptl_crystal_F_000 116 _exptl_absorpt_coefficient_mu 0.132 _exptl_absorpt_correction_type multi-scan _exptl_absorpt_correction_T_min 0.9394 _exptl_absorpt_correction_T_max 0.9974 _exptl_absorpt_process_details 'Bruker AXS SADABS program' _exptl_special_details ; Sheldrick,G.M.,(2003),University of gottingen,Germany ; _diffrn_ambient_temperature 293(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 'CCD area detector' _diffrn_measurement_method 'phi and omega scans' _diffrn_detector_area_resol_mean ? _diffrn_standards_number ? _diffrn_standards_interval_count ? _diffrn_standards_interval_time ? _diffrn_standards_decay_% ? _diffrn_reflns_number 2286 _diffrn_reflns_av_R_equivalents 0.0293 _diffrn_reflns_av_sigmaI/netI 0.0207 _diffrn_reflns_limit_h_min -4 _diffrn_reflns_limit_h_max 4 _diffrn_reflns_limit_k_min -13 _diffrn_reflns_limit_k_max 13 _diffrn_reflns_limit_l_min -6 _diffrn_reflns_limit_l_max 6 _diffrn_reflns_theta_min 3.70 _diffrn_reflns_theta_max 25.98 _reflns_number_total 455 _reflns_number_gt 401 _reflns_threshold_expression >2sigma(I) _computing_data_collection 'Bruker SMART' _computing_cell_refinement 'Bruker SMART' _computing_data_reduction 'Bruker SAINT' _computing_structure_solution 'SHELXS-97 (Sheldrick, 1990)' _computing_structure_refinement 'SHELXL-97 (Sheldrick, 1997)' _computing_molecular_graphics 'Bruker SHELXTL' _computing_publication_material 'Bruker 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^)+(0.0463P)^2^+0.0941P] 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 constr _refine_ls_extinction_method none _refine_ls_extinction_coef ? _refine_ls_number_reflns 455 _refine_ls_number_parameters 37 _refine_ls_number_restraints 0 _refine_ls_R_factor_all 0.0651 _refine_ls_R_factor_gt 0.0564 _refine_ls_wR_factor_ref 0.1220 _refine_ls_wR_factor_gt 0.1178 _refine_ls_goodness_of_fit_ref 1.240 _refine_ls_restrained_S_all 1.240 _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 0.9201(5) 0.13590(15) 0.3060(3) 0.0507(6) Uani 1 1 d . . . N1 N 0.7144(5) 0.06973(17) 0.1585(3) 0.0359(5) Uani 1 1 d . . . C1 C 0.5745(6) 0.1156(2) -0.0528(4) 0.0388(6) Uani 1 1 d . . . H1 H 0.6243 0.1955 -0.0915 0.047 Uiso 1 1 calc R . . C2 C 0.6380(6) -0.0460(2) 0.2089(4) 0.0379(6) Uani 1 1 d . . . H2 H 0.7321 -0.0791 0.3531 0.046 Uiso 1 1 calc R . . 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 0.0559(11) 0.0489(11) 0.0426(10) -0.0088(7) -0.0161(8) -0.0013(8) N1 0.0357(10) 0.0403(10) 0.0305(10) -0.0032(8) -0.0016(8) 0.0041(8) C1 0.0425(13) 0.0370(12) 0.0365(13) 0.0050(9) 0.0023(10) 0.0040(10) C2 0.0415(12) 0.0435(13) 0.0278(12) 0.0059(9) -0.0003(10) 0.0066(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 _geom_bond_site_symmetry_2 _geom_bond_publ_flag O1 N1 1.296(2) . ? N1 C2 1.343(3) . ? N1 C1 1.354(3) . ? C1 C2 1.360(3) 3_655 ? C1 H1 0.9300 . ? C2 C1 1.360(3) 3_655 ? C2 H2 0.9300 . ? 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 O1 N1 C2 121.29(18) . . ? O1 N1 C1 120.47(19) . . ? C2 N1 C1 118.23(18) . . ? N1 C1 C2 120.6(2) . 3_655 ? N1 C1 H1 119.7 . . ? C2 C1 H1 119.7 3_655 . ? N1 C2 C1 121.1(2) . 3_655 ? N1 C2 H2 119.4 . . ? C1 C2 H2 119.4 3_655 . ? _diffrn_measured_fraction_theta_max 1.000 _diffrn_reflns_theta_full 25.98 _diffrn_measured_fraction_theta_full 1.000 _refine_diff_density_max 0.218 _refine_diff_density_min -0.152 _refine_diff_density_rms 0.055