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_4120074
_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_moiety         '2(C72 H98 S2 Si1)'
_chemical_formula_sum            'C144 H196 S4 Si2'
_chemical_formula_weight         2111.43
_chemical_name_systematic
; 
 ? 
;
_space_group_IT_number           15
_symmetry_cell_setting           monoclinic
_symmetry_space_group_name_Hall  '-I 2ya'
_symmetry_space_group_name_H-M   'I 1 2/a 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                 106.830(4)
_cell_angle_gamma                90.00
_cell_formula_units_Z            8
_cell_length_a                   26.2117(18)
_cell_length_b                   18.3555(13)
_cell_length_c                   41.770(4)
_cell_measurement_reflns_used    9885
_cell_measurement_temperature    90(2)
_cell_measurement_theta_max      68.67
_cell_measurement_theta_min      4.01
_cell_volume                     19236(3)
_computing_cell_refinement       'SAINT (8.27b) (Bruker, 2012)'
_computing_data_collection       'Apex2 (2012.2-0) (Bruker, 2012)'
_computing_data_reduction        'SAINT (8.27b) (Bruker, 2012)'
_computing_molecular_graphics    'Bruker SHELXTL'
_computing_publication_material  'Bruker SHELXTL'
_computing_structure_refinement  'SHELXL-2012 (Sheldrick, 2012)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 2008)'
_diffrn_ambient_temperature      90(2)
_diffrn_measured_fraction_theta_full 0.984
_diffrn_measured_fraction_theta_max 0.984
_diffrn_measurement_device_type  'Bruker Duo APEX-II CCD'
_diffrn_measurement_method       '\f and \w scans'
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'fine-focus sealed tube'
_diffrn_radiation_type           CuK\a
_diffrn_radiation_wavelength     1.54178
_diffrn_reflns_av_R_equivalents  0.0655
_diffrn_reflns_av_sigmaI/netI    0.0699
_diffrn_reflns_limit_h_max       29
_diffrn_reflns_limit_h_min       -31
_diffrn_reflns_limit_k_max       21
_diffrn_reflns_limit_k_min       -21
_diffrn_reflns_limit_l_max       50
_diffrn_reflns_limit_l_min       -50
_diffrn_reflns_number            66921
_diffrn_reflns_theta_full        68.67
_diffrn_reflns_theta_max         68.67
_diffrn_reflns_theta_min         2.65
_exptl_absorpt_coefficient_mu    1.618
_exptl_absorpt_correction_T_max  0.7173
_exptl_absorpt_correction_T_min  0.5770
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   'SADABS 2008/1 (Sheldrick, 2008)'
_exptl_crystal_colour            yellow
_exptl_crystal_density_diffrn    1.458
_exptl_crystal_description       block
_exptl_crystal_F_000             9216
_exptl_crystal_size_max          0.38
_exptl_crystal_size_mid          0.27
_exptl_crystal_size_min          0.22
_refine_diff_density_max         3.864
_refine_diff_density_min         -1.346
_refine_diff_density_rms         0.260
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   2.420
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     1060
_refine_ls_number_reflns         17477
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      2.420
_refine_ls_R_factor_all          0.2850
_refine_ls_R_factor_gt           0.2423
_refine_ls_shift/su_max          0.451
_refine_ls_shift/su_mean         0.017
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.2000P)^2^+0.0000P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.5481
_refine_ls_wR_factor_ref         0.5918
_reflns_number_gt                11748
_reflns_number_total             17477
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            ja403802a_si_017.cif
_cod_data_source_block           bdr219b
_cod_database_code               4120074
_shelxl_version_number           2012-6