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_4110871
_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 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
_audit_creation_method           SHELXL-97
_cell_angle_alpha                90.00
_cell_angle_beta                 106.827(9)
_cell_angle_gamma                90.00
_cell_formula_units_Z            6
_cell_length_a                   14.735(4)
_cell_length_b                   5.5332(16)
_cell_length_c                   19.200(6)
_cell_measurement_temperature    297(2)
_cell_volume                     1498.4(8)
_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      297(2)
_diffrn_measured_fraction_theta_full 0.994
_diffrn_measured_fraction_theta_max 0.994
_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  0.0622
_diffrn_reflns_av_sigmaI/netI    0.0573
_diffrn_reflns_limit_h_max       17
_diffrn_reflns_limit_h_min       -19
_diffrn_reflns_limit_k_max       7
_diffrn_reflns_limit_k_min       -6
_diffrn_reflns_limit_l_max       25
_diffrn_reflns_limit_l_min       -21
_diffrn_reflns_number            12048
_diffrn_reflns_theta_full        28.28
_diffrn_reflns_theta_max         28.28
_diffrn_reflns_theta_min         2.22
_exptl_absorpt_coefficient_mu    0.074
_exptl_absorpt_correction_type   none
_exptl_crystal_colour            yellow-brow
_exptl_crystal_density_diffrn    1.225
_exptl_crystal_description       plate
_exptl_crystal_F_000             588
_refine_diff_density_max         0.195
_refine_diff_density_min         -0.244
_refine_diff_density_rms         0.056
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   0.859
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     262
_refine_ls_number_reflns         3706
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      0.859
_refine_ls_R_factor_all          0.1257
_refine_ls_R_factor_gt           0.0583
_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^)+(0.0968P)^2^+0.0000P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1410
_refine_ls_wR_factor_ref         0.1791
_reflns_number_gt                1566
_reflns_number_total             3706
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            ja063224bsi20060509_051254.cif
_cod_data_source_block           cobenz3
_cod_database_code               4110871