Pyrazine <i>N,N</i>'-dioxide
Näther, Christian; Kowallik, Petra; Jeß, Inke; Acta Crystallographica Section E 58 (2002) o1253–o1254; doi:10.1107/S1600536802018883

data_2201315
_publ_section_title
;
 Pyrazine <i>N,N</i>'-dioxide
;
_journal_issue                   11
_journal_name_full               'Acta Crystallographica Section E'
_journal_page_first              o1253
_journal_page_last               o1254
_journal_paper_doi               10.1107/S1600536802018883
_journal_volume                  58
_journal_year                    2002
_chemical_formula_iupac          'C4 H4 N2 O2'
_chemical_formula_moiety         'C4 H4 N2 O2'
_chemical_formula_sum            'C4 H4 N2 O2'
_chemical_formula_weight         112.09
_chemical_name_common            'Pyrazine dioxide'
_chemical_name_systematic
;
Pyrazine N,N'-dioxide
;
_space_group_IT_number           14
_symmetry_cell_setting           monoclinic
_symmetry_space_group_name_Hall  '-P 2ybc'
_symmetry_space_group_name_H-M   'P 1 21/c 1'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_audit_creation_method           SHELXL-97
_cell_angle_alpha                90.00
_cell_angle_beta                 96.778(19)
_cell_angle_gamma                90.00
_cell_formula_units_Z            2
_cell_length_a                   3.7376(6)
_cell_length_b                   11.0011(18)
_cell_length_c                   5.7184(9)
_cell_measurement_reflns_used    1392
_cell_measurement_temperature    293(2)
_cell_measurement_theta_max      28
_cell_measurement_theta_min      4
_cell_volume                     233.48(7)
_computing_cell_refinement       'IPDS Program Package'
_computing_data_collection       'IPDS Program Package (Stoe & Cie, 1998)'
_computing_data_reduction        'IPDS Program Package'
_computing_molecular_graphics    'XP in SHELXTL (Bruker, 1998)'
_computing_publication_material  'CIFTAB in SHELXL97'
_computing_structure_refinement  'SHELXL97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS97 (Sheldrick, 1997)'
_diffrn_ambient_temperature      293(2)
_diffrn_measured_fraction_theta_full 0.977
_diffrn_measured_fraction_theta_max 0.977
_diffrn_measurement_device_type  'Stoe IPDS'
_diffrn_measurement_method       '\f scans'
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'fine-focus sealed tube'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0319
_diffrn_reflns_av_sigmaI/netI    0.0266
_diffrn_reflns_limit_h_max       4
_diffrn_reflns_limit_h_min       -4
_diffrn_reflns_limit_k_max       11
_diffrn_reflns_limit_k_min       -14
_diffrn_reflns_limit_l_max       7
_diffrn_reflns_limit_l_min       -7
_diffrn_reflns_number            1450
_diffrn_reflns_theta_full        27.98
_diffrn_reflns_theta_max         27.98
_diffrn_reflns_theta_min         4.04
_diffrn_standards_decay_%        none
_diffrn_standards_interval_time  0
_diffrn_standards_number         0
_exptl_absorpt_coefficient_mu    0.131
_exptl_absorpt_correction_type   none
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.594
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       block
_exptl_crystal_F_000             116
_exptl_crystal_size_max          0.3
_exptl_crystal_size_mid          0.2
_exptl_crystal_size_min          0.2
_refine_diff_density_max         0.185
_refine_diff_density_min         -0.144
_refine_ls_extinction_coef       0.41(9)
_refine_ls_extinction_expression Fc^*^=kFc[1+0.001xFc^2^\l^3^/sin(2\q)]^-1/4^
_refine_ls_extinction_method     SHELXL97
_refine_ls_goodness_of_fit_ref   1.065
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     38
_refine_ls_number_reflns         551
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.065
_refine_ls_R_factor_all          0.0501
_refine_ls_R_factor_gt           0.0394
_refine_ls_shift/su_max          <0.001
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w = 1/[\s^2^(Fo^2^)+(0.0567P)^2^+0.0228P] where P = (Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0999
_refine_ls_wR_factor_ref         0.1058
_reflns_number_gt                427
_reflns_number_total             551
_reflns_threshold_expression     I>2\s(I)
_cod_data_source_file            bt6204.cif
_cod_data_source_block           I
_cod_original_cell_volume        233.48(6)
_cod_original_sg_symbol_H-M      'P 21/c'
_cod_database_code               2201315
_cod_database_fobs_code          2201315