Crystal structure of 1,3-dimethyl-5,5-dibenzylbarbituric acid, C20H20N2O3
Wei, Ya-Nan; Li, Chuan-Bi; Li, Xue; Sun, Han-Yang; Zeitschrift für Kristallographie - New Crystal Structures 232 (2017) 993–994; doi:10.1515/ncrs-2017-0124

data_8106745
_publ_section_title
;
 Crystal structure of 1,3-dimethyl-5,5-dibenzylbarbituric acid, C20H20N2O3
;
_journal_issue                   6
_journal_name_full
'Zeitschrift f\"ur Kristallographie - New Crystal Structures'
_journal_page_first              993
_journal_page_last               994
_journal_paper_doi               10.1515/ncrs-2017-0124
_journal_volume                  232
_journal_year                    2017
_chemical_formula_moiety         'C20 H20 N2 O3'
_chemical_formula_sum            'C20 H20 N2 O3'
_chemical_formula_weight         336.38
_chemical_name_systematic
;
Crystal structure of 1,3-dimethyl-5,5-disbenzyl barbituric acid
;
_space_group_IT_number           61
_space_group_name_Hall           '-P 2ac 2ab'
_space_group_name_H-M_alt        'P b c a'
_symmetry_cell_setting           orthorhombic
_symmetry_space_group_name_H-M   'P b c a'
_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                 90.00
_cell_angle_gamma                90.00
_cell_formula_units_Z            8
_cell_length_a                   9.1300(18)
_cell_length_b                   16.170(3)
_cell_length_c                   24.000(5)
_cell_measurement_reflns_used    3512
_cell_measurement_temperature    293(2)
_cell_measurement_theta_max      26.11
_cell_measurement_theta_min      1.7
_cell_volume                     3543.2(12)
_computing_cell_refinement       'Bruker SMART'
_computing_data_collection       'Bruker SMART'
_computing_data_reduction        'Bruker SAINT'
_computing_molecular_graphics    'Bruker SHELXTL'
_computing_publication_material  'Bruker SHELXTL'
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 2008)'
_computing_structure_solution    'Bruker SHELXTL'
_diffrn_ambient_temperature      293(2)
_diffrn_measured_fraction_theta_full 1.000
_diffrn_measured_fraction_theta_max 0.996
_diffrn_measurement_device_type  'CCD area detector'
_diffrn_measurement_method       'phi and omega 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  0.0285
_diffrn_reflns_av_sigmaI/netI    0.0206
_diffrn_reflns_limit_h_max       11
_diffrn_reflns_limit_h_min       -10
_diffrn_reflns_limit_k_max       16
_diffrn_reflns_limit_k_min       -20
_diffrn_reflns_limit_l_max       29
_diffrn_reflns_limit_l_min       -28
_diffrn_reflns_number            18209
_diffrn_reflns_theta_full        25.00
_diffrn_reflns_theta_max         26.11
_diffrn_reflns_theta_min         1.70
_exptl_absorpt_coefficient_mu    0.086
_exptl_absorpt_correction_T_max  0.716
_exptl_absorpt_correction_T_min  0.566
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   '(SADABS; Bruker; 2002)'
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.261
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       block
_exptl_crystal_F_000             1424
_exptl_crystal_size_max          0.32
_exptl_crystal_size_mid          0.3
_exptl_crystal_size_min          0.2
_refine_diff_density_max         0.233
_refine_diff_density_min         -0.193
_refine_diff_density_rms         0.040
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.029
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     226
_refine_ls_number_reflns         3512
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.029
_refine_ls_R_factor_all          0.0676
_refine_ls_R_factor_gt           0.0478
_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^)+(0.0732P)^2^+0.8551P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1274
_refine_ls_wR_factor_ref         0.1434
_reflns_number_gt                2556
_reflns_number_total             3512
_reflns_threshold_expression     >2\s(I)
_cod_data_source_file            suppl_ncrs-2017-0124_suppl.cif
_cod_data_source_block           a
_cod_original_sg_symbol_H-M      Pbca
_cod_database_code               8106745