2-(4-Bromophenyl)-1,2-dihydropyrimido[1,2-<i>a</i>]benzimidazol-4(3<i>H</i>)-one and 4-(4-methylphenyl)-3,4-dihydropyrimido[1,2-<i>a</i>]benzimidazol-2(1<i>H</i>)-one form hydrogen-bonded base-paired dimers
Low, John Nicolson; Cobo, Justo; Insuasty, Braulio; Nogueras, Manuel; Salcedo, Angela; Sánchez, Adolfo; Acta Crystallographica Section C 58 (2002) o125–o128; doi:10.1107/S0108270101021564

data_2012500
_publ_section_title
;2-(4-Bromophenyl)-1,2-dihydropyrimido[1,2-<i>a</i>]benzimidazol-4(3<i>H</i>)-one
 and
 4-(4-methylphenyl)-3,4-dihydropyrimido[1,2-<i>a</i>]benzimidazol-2(1<i>H</i>)-one
 form hydrogen-bonded base-paired dimers
;
_journal_issue                   2
_journal_name_full               'Acta Crystallographica Section C'
_journal_page_first              o125
_journal_page_last               o128
_journal_paper_doi               10.1107/S0108270101021564
_journal_volume                  58
_journal_year                    2002
_chemical_formula_moiety         'C16 H12 Br N3 O'
_chemical_formula_sum            'C16 H12 Br N3 O'
_chemical_formula_weight         342.20
_chemical_melting_point          577
_chemical_name_systematic
;
2-(4-Bromophenyl)-1,2-dihydropyrimido[1,2-a]benzimidazol-4(3H)-one
;
_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
_cell_angle_alpha                90
_cell_angle_beta                 111.280(2)
_cell_angle_gamma                90
_cell_formula_units_Z            4
_cell_length_a                   6.8807(2)
_cell_length_b                   16.2254(6)
_cell_length_c                   13.3379(5)
_cell_measurement_reflns_used    3046
_cell_measurement_temperature    120.0(10)
_cell_measurement_theta_max      27.44
_cell_measurement_theta_min      3.00
_cell_volume                     1387.54(9)
_computing_cell_refinement       'DENZO-SMN (Otwinowski & Minor, 1997)'
_computing_data_collection       'KappaCCD Server Software (Nonius, 1997)'
_computing_data_reduction        DENZO-SMN
_computing_molecular_graphics
'ORTEPII (Johnson, 1976) and PLATON (Spek, 2001)'
_computing_publication_material  'SHELXL97 and PRPKAPPA (Ferguson, 1999)'
_computing_structure_refinement  'SHELXL97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS97 (Sheldrick, 1997)'
_diffrn_ambient_temperature      120.0(10)
_diffrn_measured_fraction_theta_full .993
_diffrn_measured_fraction_theta_max .963
_diffrn_measurement_device_type  'Nonius KappaCCD area-detector'
_diffrn_measurement_method       '\f scans, and \w scans with \k offsets'
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'fine-focus sealed X-ray tube'
_diffrn_radiation_type           'Mo K\a'
_diffrn_radiation_wavelength     .71073
_diffrn_reflns_av_R_equivalents  .078
_diffrn_reflns_av_sigmaI/netI    .066
_diffrn_reflns_limit_h_max       8
_diffrn_reflns_limit_h_min       -8
_diffrn_reflns_limit_k_max       21
_diffrn_reflns_limit_k_min       -21
_diffrn_reflns_limit_l_max       13
_diffrn_reflns_limit_l_min       -17
_diffrn_reflns_number            8697
_diffrn_reflns_theta_full        25.00
_diffrn_reflns_theta_max         27.44
_diffrn_reflns_theta_min         3.00
_diffrn_standards_decay_%        negligible
_exptl_absorpt_coefficient_mu    2.964
_exptl_absorpt_correction_T_max  .943
_exptl_absorpt_correction_T_min  .589
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   '(DENZO-SMN; Otwinowski & Minor, 1997)'
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.638
_exptl_crystal_density_meas      ?
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       lath
_exptl_crystal_F_000             688
_exptl_crystal_size_max          .20
_exptl_crystal_size_mid          .06
_exptl_crystal_size_min          .02
_refine_diff_density_max         .71
_refine_diff_density_min         -1.55
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.010
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     190
_refine_ls_number_reflns         3046
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.010
_refine_ls_R_factor_all          .060
_refine_ls_R_factor_gt           .043
_refine_ls_shift/su_max          .001
_refine_ls_shift/su_mean         .000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'w = 1/[\s^2^(Fo^2^)+(0.0658P)^2^] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          .104
_refine_ls_wR_factor_ref         .114
_reflns_number_gt                2401
_reflns_number_total             3046
_reflns_threshold_expression     I>2\s(I)
_cod_data_source_file            gg1087.cif
_cod_data_source_block           IVa
_cod_depositor_comments
;
The following automatic conversions were performed:

'_exptl_crystal_density_meas' value 'not measured' was changed to '?'
- the value is perceived as not measured.

Automatic conversion script
Id: cif_fix_values 3008 2015-01-20 13:52:24Z robertas 
;
_cod_original_cell_volume        1387.54(8)
_cod_original_sg_symbol_H-M      'P 21/c'
_cod_database_code               2012500
_cod_database_fobs_code          2012500