Dispersion Forces and Counterintuitive Steric Effects in Main Group Molecules: Heavier Group 14 (Si-Pb) Dichalcogenolate Carbene Analogues with Sub-90° Interligand Bond Angles
Brian D. Rekken; Thomas M. Brown; James C. Fettinger; Felicitas Lips; Heikki M. Tuononen; Rolfe H. Herber; Philip P. Power; Journal of the American Chemical Society 135 (2013) 10134–10148; doi:10.1021/ja403802a

data_4120075
_publ_section_title
;
 Dispersion Forces and Counterintuitive Steric Effects in Main Group
 Molecules: Heavier Group 14 (Si-Pb) Dichalcogenolate Carbene Analogues
 with Sub-90\% Interligand Bond Angles
;
_journal_name_full               'Journal of the American Chemical Society'
_journal_page_first              10134
_journal_page_last               10148
_journal_paper_doi               10.1021/ja403802a
_journal_volume                  135
_journal_year                    2013
_chemical_formula_sum            'C146 H202 Br0.1 K1.9 O10 S4 Si'
_chemical_formula_weight         2355.68
_chemical_name_systematic
;
 ?
;
_space_group_crystal_system      monoclinic
_space_group_IT_number           15
_space_group_name_Hall           '-I 2ya'
_space_group_name_H-M_alt        'I 1 2/a 1'
_symmetry_space_group_name_Hall  '-I 2ya'
_symmetry_space_group_name_H-M   'I 1 2/a 1'
_atom_sites_solution_hydrogens   geom
_audit_creation_method           SHELXL-2012
_cell_angle_alpha                90
_cell_angle_beta                 94.862(2)
_cell_angle_gamma                90
_cell_formula_units_Z            4
_cell_length_a                   16.7748(8)
_cell_length_b                   16.8855(8)
_cell_length_c                   47.454(2)
_cell_measurement_temperature    90(2)
_cell_volume                     13393.0(11)
_computing_structure_refinement  'SHELXL-2012 (Sheldrick, 2012)'
_diffrn_ambient_temperature      90(2)
_diffrn_measured_fraction_theta_full 0.992
_diffrn_measured_fraction_theta_max 0.991
_diffrn_radiation_type           CuK\a
_diffrn_radiation_wavelength     1.54178
_diffrn_reflns_av_R_equivalents  0.0266
_diffrn_reflns_av_unetI/netI     0.0338
_diffrn_reflns_Laue_measured_fraction_full 0.992
_diffrn_reflns_Laue_measured_fraction_max 0.991
_diffrn_reflns_limit_h_max       20
_diffrn_reflns_limit_h_min       -19
_diffrn_reflns_limit_k_max       20
_diffrn_reflns_limit_k_min       -20
_diffrn_reflns_limit_l_max       56
_diffrn_reflns_limit_l_min       -57
_diffrn_reflns_number            30011
_diffrn_reflns_point_group_measured_fraction_full 0.992
_diffrn_reflns_point_group_measured_fraction_max 0.991
_diffrn_reflns_theta_full        67.679
_diffrn_reflns_theta_max         68.245
_diffrn_reflns_theta_min         2.779
_exptl_absorpt_coefficient_mu    1.738
_exptl_crystal_density_diffrn    1.168
_exptl_crystal_F_000             5102
_refine_diff_density_max         0.623
_refine_diff_density_min         -0.567
_refine_diff_density_rms         0.055
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.021
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     845
_refine_ls_number_reflns         12164
_refine_ls_number_restraints     155
_refine_ls_restrained_S_all      1.158
_refine_ls_R_factor_all          0.0588
_refine_ls_R_factor_gt           0.0545
_refine_ls_shift/su_max          0.003
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
;
 w=1/[\s^2^(Fo^2^)+(0.0576P)^2^+33.5790P]
 where P=(Fo^2^+2Fc^2^)/3
;
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1382
_refine_ls_wR_factor_ref         0.1420
_reflns_Friedel_coverage         0.000
_reflns_number_gt                11089
_reflns_number_total             12164
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            ja403802a_si_018.cif
_cod_data_source_block           BDR229FMI
_cod_original_formula_sum        'C146 H202 Br0.10 K1.90 O10 S4 Si'
_cod_database_code               4120075
_shelxl_version_number           2012-6
_shelx_res_checksum              62374