1,4-Bis(dibromomethylidene)cyclohexane: crystal packing with Br···Br and Br···π contacts
Jones, Peter G.; Kämpen, Jan; Bubenitschek, Peter; Hopf, Henning; Acta Crystallographica Section E 61 (2005) o2179–o2180; doi:10.1107/S1600536805018374

data_2206137
_publ_section_title
;
 1,4-Bis(dibromomethylidene)cyclohexane: crystal packing with
 Br&#x00B7;&#x00B7;&#x00B7;Br and Br&#x00B7;&#x00B7;&#x00B7;\p contacts
;
_journal_issue                   7
_journal_name_full               'Acta Crystallographica Section E'
_journal_page_first              o2179
_journal_page_last               o2180
_journal_paper_doi               10.1107/S1600536805018374
_journal_volume                  61
_journal_year                    2005
_chemical_formula_iupac          'C8 H8 Br4'
_chemical_formula_moiety         'C8 H8 Br4'
_chemical_formula_sum            'C8 H8 Br4'
_chemical_formula_weight         423.78
_chemical_name_systematic
;
1,4-Bis(dibromomethylidene)cyclohexane
;
_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                 102.783(12)
_cell_angle_gamma                90.00
_cell_formula_units_Z            2
_cell_length_a                   6.6033(10)
_cell_length_b                   12.3957(18)
_cell_length_c                   6.7152(10)
_cell_measurement_reflns_used    62
_cell_measurement_temperature    173(2)
_cell_measurement_theta_max      12.5
_cell_measurement_theta_min      3.5
_cell_volume                     536.03(14)
_computing_cell_refinement       XSCANS
_computing_data_collection       'XSCANS (Fait, 1991)'
_computing_data_reduction        XSCANS
_computing_molecular_graphics    'XP5 (Siemens, 1994)'
_computing_publication_material  SHELXL97
_computing_structure_refinement  'SHELXL97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS97 (Sheldrick, 1990)'
_diffrn_ambient_temperature      173(2)
_diffrn_measured_fraction_theta_full 0.957
_diffrn_measured_fraction_theta_max 0.957
_diffrn_measurement_device_type  'Siemens P4'
_diffrn_measurement_method       \w
_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  0.0755
_diffrn_reflns_av_sigmaI/netI    0.0614
_diffrn_reflns_limit_h_max       7
_diffrn_reflns_limit_h_min       -7
_diffrn_reflns_limit_k_max       14
_diffrn_reflns_limit_k_min       0
_diffrn_reflns_limit_l_max       7
_diffrn_reflns_limit_l_min       0
_diffrn_reflns_number            973
_diffrn_reflns_theta_full        25.00
_diffrn_reflns_theta_max         25.00
_diffrn_reflns_theta_min         3.29
_diffrn_standards_decay_%        0
_diffrn_standards_interval_count 247
_diffrn_standards_number         3
_exptl_absorpt_coefficient_mu    14.961
_exptl_absorpt_correction_T_max  0.95
_exptl_absorpt_correction_T_min  0.30
_exptl_absorpt_correction_type   psi-scan
_exptl_absorpt_process_details   '(XEMP; Siemens, 1994)'
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    2.626
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       tablet
_exptl_crystal_F_000             392
_exptl_crystal_size_max          0.4
_exptl_crystal_size_mid          0.3
_exptl_crystal_size_min          0.15
_refine_diff_density_max         0.964
_refine_diff_density_min         -0.713
_refine_ls_extinction_coef       0.043(4)
_refine_ls_extinction_expression Fc^*^=kFc[1+0.001xFc^2^\l^3^/sin(2\q)]^-1/4^
_refine_ls_extinction_method     SHELXL97
_refine_ls_goodness_of_fit_ref   1.126
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     56
_refine_ls_number_reflns         901
_refine_ls_number_restraints     5
_refine_ls_restrained_S_all      1.123
_refine_ls_R_factor_all          0.0652
_refine_ls_R_factor_gt           0.0415
_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^)+(0.0640P)^2^] where P = (Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0976
_refine_ls_wR_factor_ref         0.1051
_reflns_number_gt                738
_reflns_number_total             901
_reflns_threshold_expression     I>2\s(I)
_cod_data_source_file            bt6681.cif
_cod_data_source_block           2
_cod_original_sg_symbol_H-M      'P 21/n'
_cod_database_code               2206137
_cod_database_fobs_code          2206137