Diimidazo[1,5-<i>a</i>;1',5'-<i>d</i>]pyrazine-5,10-dione
Castillejo Merchán, Alejandro; Stoeckli-Evans, Helen; Acta Crystallographica Section E 63 (2007) o636–o637; doi:10.1107/S160053680700061X

data_2212192
_publ_section_title
;
 Diimidazo[1,5-<i>a</i>;1',5'-<i>d</i>]pyrazine-5,10-dione
;
_journal_coeditor_code           HB2254
_journal_issue                   2
_journal_name_full               'Acta Crystallographica Section E'
_journal_page_first              o636
_journal_page_last               o637
_journal_paper_doi               10.1107/S160053680700061X
_journal_volume                  63
_journal_year                    2007
_chemical_formula_iupac          'C8 H4 N4 O2'
_chemical_formula_moiety         'C8 H4 N4 O2'
_chemical_formula_sum            'C8 H4 N4 O2'
_chemical_formula_weight         188.15
_chemical_name_systematic
;
Diimidazo[1,5-a;1',5'-d]pyrazine-5,10-dione
;
_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   difmap
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_audit_creation_method           SHELXL-97
_cell_angle_alpha                90.00
_cell_angle_beta                 96.23(3)
_cell_angle_gamma                90.00
_cell_formula_units_Z            2
_cell_length_a                   5.4047(19)
_cell_length_b                   6.9777(18)
_cell_length_c                   9.678(4)
_cell_measurement_reflns_used    2055
_cell_measurement_temperature    173(2)
_cell_measurement_theta_max      25.99
_cell_measurement_theta_min      3.61
_cell_volume                     362.8(2)
_computing_cell_refinement       X-AREA
_computing_data_collection       'X-AREA (Stoe & Cie, 2005)'
_computing_data_reduction        'X-RED32 (Stoe & Cie, 2005)'
_computing_molecular_graphics    'PLATON  (Spek, 2003)'
_computing_publication_material  SHELXL97
_computing_structure_refinement  'SHELXL97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS97 (Sheldrick, 1997)'
_diffrn_ambient_temperature      173(2)
_diffrn_detector_area_resol_mean 6.67
_diffrn_measured_fraction_theta_full 0.674
_diffrn_measured_fraction_theta_max 0.681
_diffrn_measurement_device_type  'Stoe IPDS-2'
_diffrn_measurement_method       '\w and \f'
_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  0.0509
_diffrn_reflns_av_sigmaI/netI    0.0442
_diffrn_reflns_limit_h_max       6
_diffrn_reflns_limit_h_min       -6
_diffrn_reflns_limit_k_max       8
_diffrn_reflns_limit_k_min       -8
_diffrn_reflns_limit_l_max       11
_diffrn_reflns_limit_l_min       -11
_diffrn_reflns_number            1582
_diffrn_reflns_theta_full        25.00
_diffrn_reflns_theta_max         25.62
_diffrn_reflns_theta_min         4.79
_diffrn_standards_decay_%        0
_diffrn_standards_number         0
_exptl_absorpt_coefficient_mu    0.131
_exptl_absorpt_correction_type   none
_exptl_crystal_colour            'pale yellow'
_exptl_crystal_density_diffrn    1.722
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       rod
_exptl_crystal_F_000             192
_exptl_crystal_size_max          0.23
_exptl_crystal_size_mid          0.13
_exptl_crystal_size_min          0.10
_refine_diff_density_max         0.191
_refine_diff_density_min         -0.155
_refine_ls_extinction_coef       0.065(16)
_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   0.968
_refine_ls_hydrogen_treatment    refall
_refine_ls_matrix_type           full
_refine_ls_number_parameters     73
_refine_ls_number_reflns         471
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      0.968
_refine_ls_R_factor_all          0.0641
_refine_ls_R_factor_gt           0.0412
_refine_ls_shift/su_max          0.000
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0657P)^2^] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0950
_refine_ls_wR_factor_ref         0.1037
_reflns_number_gt                338
_reflns_number_total             471
_reflns_threshold_expression     I>2\s(I)
_cod_data_source_file            hb2254.cif
_cod_data_source_block           I
_cod_original_sg_symbol_H-M      'P 21/c'
_cod_database_code               2212192
_cod_database_fobs_code          2212192