1,1'-Bis(4-fluorobenzyl)-3,3'-methylenediimidazolium dibromide
Cheng, Pi-Yun; Chen, Chih-Yuen; Lee, Hon Man; Acta Crystallographica Section E 62 (2006) o5850–o5851; doi:10.1107/S1600536806050173

data_2211520
_publ_section_title
;
 1,1'-Bis(4-fluorobenzyl)-3,3'-methylenediimidazolium dibromide
;
_journal_coeditor_code           LH2249
_journal_issue                   12
_journal_name_full               'Acta Crystallographica Section E'
_journal_page_first              o5850
_journal_page_last               o5851
_journal_paper_doi               10.1107/S1600536806050173
_journal_volume                  62
_journal_year                    2006
_chemical_formula_iupac          'C21 H20 F2 N4 2+, 2Br -'
_chemical_formula_moiety         'C21 H20 F2 N4 2+, 2(Br -)'
_chemical_formula_sum            'C21 H20 Br2 F2 N4'
_chemical_formula_weight         526.23
_chemical_name_systematic
;
1,1'-Bis(4-fluorobenzyl)-3,3'-methylenediimidazolium dibromide
;
_space_group_IT_number           15
_symmetry_cell_setting           monoclinic
_symmetry_space_group_name_Hall  '-C 2yc'
_symmetry_space_group_name_H-M   'C 1 2/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                 104.930(10)
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   33.465(11)
_cell_length_b                   5.375(2)
_cell_length_c                   12.077(4)
_cell_measurement_reflns_used    1175
_cell_measurement_temperature    298(2)
_cell_measurement_theta_max      21.6
_cell_measurement_theta_min      2.5
_cell_volume                     2099.0(13)
_computing_cell_refinement       'SAINT (Bruker, 2001)'
_computing_data_collection       'SMART (Bruker, 2001)'
_computing_data_reduction        SAINT
_computing_molecular_graphics    SHELXTL
_computing_publication_material  SHELXTL
_computing_structure_refinement  SHELXTL
_computing_structure_solution    'SHELXTL (Sheldrick, 1998)'
_diffrn_ambient_temperature      150(2)
_diffrn_measured_fraction_theta_full 0.989
_diffrn_measured_fraction_theta_max 0.989
_diffrn_measurement_device_type  'Bruker SMART 1000'
_diffrn_measurement_method       \w
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0688
_diffrn_reflns_av_sigmaI/netI    0.0982
_diffrn_reflns_limit_h_max       44
_diffrn_reflns_limit_h_min       -43
_diffrn_reflns_limit_k_max       7
_diffrn_reflns_limit_k_min       -4
_diffrn_reflns_limit_l_max       15
_diffrn_reflns_limit_l_min       -12
_diffrn_reflns_number            6381
_diffrn_reflns_theta_full        28.00
_diffrn_reflns_theta_max         28.00
_diffrn_reflns_theta_min         2.52
_diffrn_standards_decay_%        0
_diffrn_standards_interval_count 0
_diffrn_standards_interval_time  0
_diffrn_standards_number         0
_exptl_absorpt_coefficient_mu    3.892
_exptl_absorpt_correction_T_max  0.4960
_exptl_absorpt_correction_T_min  0.3512
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   '(SADABS; Sheldrick, 2002)'
_exptl_crystal_colour            colorless
_exptl_crystal_density_diffrn    1.664
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       Parallelepiped
_exptl_crystal_F_000             1048
_exptl_crystal_size_max          0.34
_exptl_crystal_size_mid          0.20
_exptl_crystal_size_min          0.18
_refine_diff_density_max         0.582
_refine_diff_density_min         -0.401
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   0.982
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     132
_refine_ls_number_reflns         2506
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      0.982
_refine_ls_R_factor_all          0.1199
_refine_ls_R_factor_gt           0.0471
_refine_ls_shift/su_max          0.001
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0473P)^2^] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0970
_refine_ls_wR_factor_ref         0.1225
_reflns_number_gt                1339
_reflns_number_total             2506
_reflns_threshold_expression     I>2\s(I)
_cod_data_source_file            lh2249.cif
_cod_data_source_block           I
_cod_original_sg_symbol_H-M      'C 2/c'
_cod_database_code               2211520
_cod_database_fobs_code          2211520