The regioselectivity and synthetic mechanism of 1,2-benzimidazole squaraines: combined experimental and theoretical studies
Xia, Guomin; Wu, Zhiwei; Yuan, Yanli; Wang, Hongming; RSC Advances 3 (2013) 18055–; doi:10.1039/c3ra43608j

data_7239221
_publ_section_title
;
 The regioselectivity and synthetic mechanism of 1,2-benzimidazole
 squaraines: combined experimental and theoretical studies
;
_journal_issue                   39
_journal_name_full               'RSC Advances'
_journal_page_first              18055
_journal_paper_doi               10.1039/c3ra43608j
_journal_volume                  3
_journal_year                    2013
_chemical_formula_moiety         'C48 H38 N4 O2'
_chemical_formula_sum            'C48 H38 N4 O2'
_chemical_formula_weight         702.82
_space_group_IT_number           15
_space_group_name_Hall           '-C 2yc'
_space_group_name_H-M_alt        'C 1 2/c 1'
_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                 94.994(3)
_cell_angle_gamma                90.00
_cell_formula_units_Z            8
_cell_length_a                   25.957(6)
_cell_length_b                   11.995(3)
_cell_length_c                   23.968(5)
_cell_measurement_reflns_used    3457
_cell_measurement_temperature    296(2)
_cell_measurement_theta_max      28.38
_cell_measurement_theta_min      2.42
_cell_volume                     7434(3)
_computing_cell_refinement       'SAINT, v6.0 (Bruker AXS, 2004)'
_computing_data_collection       'SMART, v6.0 (Bruker AXS, 2004)'
_computing_data_reduction        'SAINT, v6.0 (Bruker AXS, 2004)'
_computing_molecular_graphics    'ORTEP3 for Windows (Farrugia, 1997)'
_computing_publication_material  'SHELXL-97 (Sheldrick, 2008)'
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 2008)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 2008)'
_diffrn_ambient_temperature      296(2)
_diffrn_measured_fraction_theta_full 0.837
_diffrn_measured_fraction_theta_max 0.837
_diffrn_measurement_device_type  'Bruker Apex-II CCD diffractometer'
_diffrn_measurement_method       'Thin slice \f & \w 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  0.0788
_diffrn_reflns_av_sigmaI/netI    0.1300
_diffrn_reflns_limit_h_max       33
_diffrn_reflns_limit_h_min       -14
_diffrn_reflns_limit_k_max       13
_diffrn_reflns_limit_k_min       -15
_diffrn_reflns_limit_l_max       27
_diffrn_reflns_limit_l_min       -31
_diffrn_reflns_number            12146
_diffrn_reflns_theta_full        28.35
_diffrn_reflns_theta_max         28.35
_diffrn_reflns_theta_min         2.22
_exptl_absorpt_coefficient_mu    0.077
_exptl_absorpt_correction_T_max  0.979
_exptl_absorpt_correction_T_min  0.973
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   'SADABS, v2.10 (Sheldrick, G.M., 2003)'
_exptl_crystal_colour            yellow
_exptl_crystal_density_diffrn    1.256
_exptl_crystal_density_meas      0
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       block
_exptl_crystal_F_000             2960
_exptl_crystal_size_max          0.36
_exptl_crystal_size_mid          0.30
_exptl_crystal_size_min          0.28
_refine_diff_density_max         0.219
_refine_diff_density_min         -0.236
_refine_diff_density_rms         0.046
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.080
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     487
_refine_ls_number_reflns         7754
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.080
_refine_ls_R_factor_all          0.2049
_refine_ls_R_factor_gt           0.1005
_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^)+(0.0485P)^2^+7.0856P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1617
_refine_ls_wR_factor_ref         0.2009
_reflns_number_gt                3587
_reflns_number_total             7754
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            c3ra43608j.txt
_cod_data_source_block           t
_cod_original_sg_symbol_H-M      'C 2/c'
_cod_database_code               7239221