Serendipity and Four Polymorphic Structures of Benzidine, C12H12N2
Michal Rafilovich; Joel Bernstein; Journal of the American Chemical Society 128 (2006) 12185–12191; doi:10.1021/ja063224b

data_4110872
_publ_section_title
;
 Serendipity and Four Polymorphic Structures of Benzidine, C12H12N2
;
_journal_name_full               'Journal of the American Chemical Society'
_journal_page_first              12185
_journal_page_last               12191
_journal_paper_doi               10.1021/ja063224b
_journal_volume                  128
_journal_year                    2006
_chemical_formula_sum            'C12 H12 N2'
_chemical_formula_weight         184.24
_space_group_IT_number           14
_symmetry_cell_setting           monoclinic
_symmetry_space_group_name_Hall  '-P 2yn'
_symmetry_space_group_name_H-M   'P 1 21/n 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                 99.153(3)
_cell_angle_gamma                90.00
_cell_formula_units_Z            18
_cell_length_a                   11.6310(13)
_cell_length_b                   16.1892(19)
_cell_length_c                   24.173(3)
_cell_measurement_temperature    298(2)
_cell_volume                     4493.7(9)
_computing_cell_refinement       'Bruker SMART'
_computing_data_collection       'Bruker SMART'
_computing_data_reduction        'Bruker SHELXTL'
_computing_molecular_graphics    'Bruker SHELXTL'
_computing_publication_material  'Bruker SHELXTL'
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1990)'
_diffrn_ambient_temperature      298(2)
_diffrn_measured_fraction_theta_full 0.998
_diffrn_measured_fraction_theta_max 0.998
_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  0.0694
_diffrn_reflns_av_sigmaI/netI    0.0766
_diffrn_reflns_limit_h_max       15
_diffrn_reflns_limit_h_min       -15
_diffrn_reflns_limit_k_max       21
_diffrn_reflns_limit_k_min       -18
_diffrn_reflns_limit_l_max       32
_diffrn_reflns_limit_l_min       -32
_diffrn_reflns_number            39061
_diffrn_reflns_theta_full        28.33
_diffrn_reflns_theta_max         28.33
_diffrn_reflns_theta_min         1.52
_exptl_absorpt_coefficient_mu    0.074
_exptl_absorpt_correction_type   none
_exptl_crystal_colour            brown
_exptl_crystal_density_diffrn    1.225
_exptl_crystal_description       needle
_exptl_crystal_F_000             1764
_refine_diff_density_max         0.144
_refine_diff_density_min         -0.193
_refine_diff_density_rms         0.037
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   0.843
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     764
_refine_ls_number_reflns         11194
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      0.843
_refine_ls_R_factor_all          0.1611
_refine_ls_R_factor_gt           0.0478
_refine_ls_shift/su_max          0.116
_refine_ls_shift/su_mean         0.005
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0710P)^2^+0.0000P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1137
_refine_ls_wR_factor_ref         0.1625
_reflns_number_gt                3875
_reflns_number_total             11194
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            ja063224bsi20060509_051310.cif
_cod_data_source_block           cobenz3
_cod_database_code               4110872