1,4-Dibromo-2,5-dimethoxybenzene
Luo, Zhong-Hua; Chang, Jin; Feng, Mei-Li; Zhang, Qin; Zhu, Hong-Jun; Acta Crystallographica Section E 66 (2010) o1806–; doi:10.1107/S1600536810023548

data_2226527
_publ_section_title
;
 1,4-Dibromo-2,5-dimethoxybenzene
;
_journal_issue                   7
_journal_name_full               'Acta Crystallographica Section E'
_journal_page_first              o1806
_journal_paper_doi               10.1107/S1600536810023548
_journal_volume                  66
_journal_year                    2010
_chemical_formula_iupac          'C8 H8 Br2 O2'
_chemical_formula_moiety         'C8 H8 Br2 O2'
_chemical_formula_sum            'C8 H8 Br2 O2'
_chemical_formula_weight         295.94
_chemical_name_systematic
;
1,4-Dibromo-2,5-dimethoxybenzene
;
_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                 90.14(3)
_cell_angle_gamma                90.00
_cell_formula_units_Z            2
_cell_length_a                   6.5730(10)
_cell_length_b                   8.438(2)
_cell_length_c                   8.756(2)
_cell_measurement_reflns_used    25
_cell_measurement_temperature    298(2)
_cell_measurement_theta_max      13
_cell_measurement_theta_min      9
_cell_volume                     485.63(18)
_computing_cell_refinement       'CAD-4 Software (Enraf--Nonius, 1985)'
_computing_data_collection       'CAD-4 Software (Enraf--Nonius, 1985)'
_computing_data_reduction        'XCAD4 (Harms & Wocadlo, 1995)'
_computing_molecular_graphics    'SHELXTL (Sheldrick, 2008)'
_computing_publication_material  'SHELXTL (Sheldrick, 2008)'
_computing_structure_refinement  'SHELXL97 (Sheldrick, 2008)'
_computing_structure_solution    'SHELXS97 (Sheldrick, 2008)'
_diffrn_ambient_temperature      298(2)
_diffrn_measured_fraction_theta_full 1.000
_diffrn_measured_fraction_theta_max 1.000
_diffrn_measurement_device_type  'Enraf--Nonius CAD-4'
_diffrn_measurement_method       \w/2\q
_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  0.1123
_diffrn_reflns_av_sigmaI/netI    0.1146
_diffrn_reflns_limit_h_max       7
_diffrn_reflns_limit_h_min       -7
_diffrn_reflns_limit_k_max       0
_diffrn_reflns_limit_k_min       -10
_diffrn_reflns_limit_l_max       10
_diffrn_reflns_limit_l_min       -10
_diffrn_reflns_number            1761
_diffrn_reflns_theta_full        25.29
_diffrn_reflns_theta_max         25.29
_diffrn_reflns_theta_min         3.35
_diffrn_standards_decay_%        1
_diffrn_standards_interval_count 200
_diffrn_standards_interval_time  120
_diffrn_standards_number         3
_exptl_absorpt_coefficient_mu    8.303
_exptl_absorpt_correction_T_max  0.4906
_exptl_absorpt_correction_T_min  0.2875
_exptl_absorpt_correction_type   psi-scan
_exptl_absorpt_process_details   '(North <i>et al.</i>,  1968)'
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    2.024
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       block
_exptl_crystal_F_000             284
_exptl_crystal_size_max          0.20
_exptl_crystal_size_mid          0.10
_exptl_crystal_size_min          0.10
_refine_diff_density_max         0.576
_refine_diff_density_min         -0.410
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.009
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     55
_refine_ls_number_reflns         884
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.009
_refine_ls_R_factor_all          0.0707
_refine_ls_R_factor_gt           0.0439
_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^)+(0.03P)^2^+0.00P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0939
_refine_ls_wR_factor_ref         0.1021
_reflns_number_gt                622
_reflns_number_total             884
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            im2205.cif
_cod_data_source_block           I
_cod_original_cell_volume        485.6(2)
_cod_original_sg_symbol_H-M      'P 21/n'
_cod_database_code               2226527
_cod_database_fobs_code          2226527