Hydrogen-bond patterns in 1,4-dihydro-2,3-quinoxalinediones: ligands for the glycine modulatory site on the NMDA receptor
Kubicki, M.; Kindopp, T. W.; Capparelli, M. V.; Codding, P. W.; Acta Crystallographica Section B 52 (1996) 487–499; doi:10.1107/S0108768195011773

data_2101518
_publ_section_title
;
 Hydrogen-bond patterns in 1,4-dihydro-2,3-quinoxalinediones: ligands
 for the glycine modulatory site on the NMDA receptor
;
_journal_issue                   3
_journal_name_full               'Acta Crystallographica Section B'
_journal_page_first              487
_journal_page_last               499
_journal_paper_doi               10.1107/S0108768195011773
_journal_volume                  52
_journal_year                    1996
_chemical_formula_sum            'C8 H4 N4 O6'
_chemical_formula_weight         252.15
_symmetry_cell_setting           monoclinic
_symmetry_space_group_name_Hall  '-P 2ybc'
_symmetry_space_group_name_H-M   'P 1 21/c 1'
_atom_type_scat_source           IntTabC
_cell_angle_alpha                90
_cell_angle_beta                 90.341(3)
_cell_angle_gamma                90
_cell_formula_units_Z            4
_cell_length_a                   8.4668(3)
_cell_length_b                   8.5533(4)
_cell_length_c                   12.4657(6)
_cell_measurement_reflns_used    25
_cell_measurement_temperature    293(2)
_cell_measurement_theta_max      43.61
_cell_measurement_theta_min      19.58
_cell_volume                     902.74(7)
_computing_cell_refinement       'SHELXL03 (Sheldrick, 1993)'
_computing_data_collection       'Enraf-Nonius CAD-4F'
_computing_data_reduction        'ENDROC (Rettig, 1978)'
_computing_structure_refinement  'SHELXL93 (Sheldrick, 1993)'
_computing_structure_solution    'SHELXS86 (Sheldrick, 1990)'
_diffrn_measurement_device       'Enraf-Nonius CAD-4F'
_diffrn_measurement_method       \w-2\q
_diffrn_radiation_type           CuK\a
_diffrn_radiation_wavelength     1.54178
_diffrn_reflns_av_R_equivalents  0.0451
_diffrn_reflns_limit_h_max       10
_diffrn_reflns_limit_h_min       -8
_diffrn_reflns_limit_k_max       10
_diffrn_reflns_limit_k_min       -5
_diffrn_reflns_limit_l_max       15
_diffrn_reflns_limit_l_min       -15
_diffrn_reflns_number            3846
_diffrn_reflns_theta_max         74.87
_diffrn_standards_decay_%        <3
_diffrn_standards_interval_time  33.33
_diffrn_standards_number         3
_exptl_absorpt_coefficient_mu    1.439
_exptl_absorpt_correction_type   none
_exptl_crystal_colour            yellow
_exptl_crystal_density_diffrn    1.855
_exptl_crystal_description       prism
_exptl_crystal_F_000             512
_exptl_crystal_size_max          0.34
_exptl_crystal_size_mid          0.22
_exptl_crystal_size_min          0.16
_refine_diff_density_max         0.242
_refine_diff_density_min         -0.172
_refine_ls_extinction_coef       0.0070(10)
_refine_ls_extinction_method     'SHELXL93 (Sheldrick, 1993)'
_refine_ls_goodness_of_fit_obs   1.051
_refine_ls_hydrogen_treatment    refall
_refine_ls_number_parameters     180
_refine_ls_number_reflns         1851
_refine_ls_R_factor_obs          0.0314
_refine_ls_shift/esd_max         0.001
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_scheme
;w = 1/[\s^2^(F^2^) + (0.0296P)^2^ + 0.2334P]
where P = (F~o~^2^ + 2F~c~^2^)/3
;
_refine_ls_wR_factor_obs         0.0874
_reflns_number_observed          1730
_reflns_number_total             1854
_reflns_observed_criterion       I>2\s(I)
_cod_data_source_file            cr0473.cif
_cod_data_source_block           cr0473a
_cod_database_code               2101518