NHC-Stabilized Silicon-Carbon Mixed Cumulene.
Wang, Zhendong; Zhang, Jianying; Li, Jianfeng; Cui, Chunming; Journal of the American Chemical Society 138 (2016) 10421–10424; doi:10.1021/jacs.6b06960

data_4125183
_publ_section_title
;
 NHC-Stabilized Silicon-Carbon Mixed Cumulene.
;
_journal_issue                   33
_journal_name_full               'Journal of the American Chemical Society'
_journal_page_first              10421
_journal_page_last               10424
_journal_paper_doi               10.1021/jacs.6b06960
_journal_volume                  138
_journal_year                    2016
_chemical_absolute_configuration unk
_chemical_formula_sum            'C32 H48 N2 Si3'
_chemical_formula_weight         544.99
_space_group_crystal_system      orthorhombic
_space_group_IT_number           19
_space_group_name_Hall           'P 2ac 2ab'
_space_group_name_H-M_alt        'P 21 21 21'
_symmetry_space_group_name_Hall  'P 2ac 2ab'
_symmetry_space_group_name_H-M   'P 21 21 21'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_audit_creation_method           SHELXL-2014/7
_cell_angle_alpha                90
_cell_angle_beta                 90
_cell_angle_gamma                90
_cell_formula_units_Z            4
_cell_length_a                   9.8511(14)
_cell_length_b                   16.512(3)
_cell_length_c                   20.180(3)
_cell_measurement_reflns_used    5003
_cell_measurement_temperature    113(2)
_cell_measurement_theta_max      27.4
_cell_measurement_theta_min      3.1
_cell_volume                     3282.5(9)
_computing_cell_refinement       'CrystalClear-SM Expert 2.0 r2'
_computing_data_collection
'CrystalClear-SM Expert 2.0 r2 (Rigaku, 2009)'
_computing_data_reduction        'CrystalClear-SM Expert 2.0 r2'
_computing_molecular_graphics    'Bruker SHELXTL'
_computing_publication_material  'Bruker SHELXTL'
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1990)'
_diffrn_ambient_temperature      113(2)
_diffrn_detector_area_resol_mean 14.6
_diffrn_measured_fraction_theta_full 0.997
_diffrn_measured_fraction_theta_max 0.997
_diffrn_measurement_device_type  'Rigaku Saturn 724CCD camera'
_diffrn_measurement_method       \w
_diffrn_radiation_monochromator  Multilayer
_diffrn_radiation_source         'Rotating Anode'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0562
_diffrn_reflns_av_unetI/netI     0.0454
_diffrn_reflns_Laue_measured_fraction_full 0.997
_diffrn_reflns_Laue_measured_fraction_max 0.997
_diffrn_reflns_limit_h_max       12
_diffrn_reflns_limit_h_min       -12
_diffrn_reflns_limit_k_max       21
_diffrn_reflns_limit_k_min       -21
_diffrn_reflns_limit_l_max       26
_diffrn_reflns_limit_l_min       -26
_diffrn_reflns_number            42201
_diffrn_reflns_point_group_measured_fraction_full 0.998
_diffrn_reflns_point_group_measured_fraction_max 0.997
_diffrn_reflns_theta_full        25.242
_diffrn_reflns_theta_max         27.507
_diffrn_reflns_theta_min         3.142
_exptl_absorpt_coefficient_mu    0.167
_exptl_absorpt_correction_T_max  0.7618
_exptl_absorpt_correction_T_min  0.7199
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   crystalclear
_exptl_crystal_colour            red
_exptl_crystal_density_diffrn    1.103
_exptl_crystal_description       prism
_exptl_crystal_F_000             1184
_exptl_crystal_size_max          0.220
_exptl_crystal_size_mid          0.200
_exptl_crystal_size_min          0.180
_refine_diff_density_max         0.270
_refine_diff_density_min         -0.186
_refine_diff_density_rms         0.046
_refine_ls_abs_structure_details
;
 Flack x determined using 2435 quotients [(I+)-(I-)]/[(I+)+(I-)]
 (Parsons, Flack and Wagner, Acta Cryst. B69 (2013) 249-259).
;
_refine_ls_abs_structure_Flack   0.12(4)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   0.831
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     346
_refine_ls_number_reflns         7528
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      0.831
_refine_ls_R_factor_all          0.0555
_refine_ls_R_factor_gt           0.0399
_refine_ls_shift/su_max          0.000
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'w=1/[\s^2^(Fo^2^)+(0.1000P)^2^+0.4088P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1055
_refine_ls_wR_factor_ref         0.1190
_reflns_Friedel_coverage         0.790
_reflns_Friedel_fraction_full    1.000
_reflns_Friedel_fraction_max     0.998
_reflns_number_gt                6379
_reflns_number_total             7528
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            ja6b06960_si_004.cif
_cod_data_source_block           m20151227c
_cod_depositor_comments
'Adding full bibliography for 4125183--4125184.cif.'
_cod_original_cell_volume        3282.6(8)
_cod_database_code               4125183
_shelx_shelxl_version_number     2014/7
_shelx_estimated_absorpt_t_min   0.964
_shelx_estimated_absorpt_t_max   0.971
_shelx_res_checksum              86150
_shelx_hkl_checksum              40516