Isolable p- and m-[(tBu2MeSi)2Si]2C6H4: Disilaquinodimethane vs Triplet Bis(silyl radical)
Takeshi Nozawa; Michiyo Nagata; Masaaki Ichinohe; Akira Sekiguchi; Journal of the American Chemical Society 133 (2011) 5773–5775; doi:10.1021/ja2014746

data_4106000
_publ_section_title
;
 Isolable p- and m-[(tBu2MeSi)2Si]2C6H4: Disilaquinodimethane vs Triplet
 Bis(silyl radical)
;
_journal_name_full               'Journal of the American Chemical Society'
_journal_page_first              5773
_journal_page_last               5775
_journal_paper_doi               10.1021/ja2014746
_journal_volume                  133
_journal_year                    2011
_chemical_formula_sum            'C42 H88 Si6'
_chemical_formula_weight         761.66
_chemical_name_systematic
; 
 3,6-Bis[Bis(di-tert-butylmethylsilyl)silylene]cyclohexa-1,4-diene 
;
_space_group_IT_number           14
_symmetry_cell_setting           monoclinic
_symmetry_space_group_name_Hall  '-P 2ybc'
_symmetry_space_group_name_H-M   'P 1 21/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                 109.1140(10)
_cell_angle_gamma                90.00
_cell_formula_units_Z            2
_cell_length_a                   14.9622(17)
_cell_length_b                   11.7270(13)
_cell_length_c                   15.0608(17)
_cell_measurement_reflns_used    9892
_cell_measurement_temperature    120.0(1)
_cell_measurement_theta_max      28.39
_cell_measurement_theta_min      2.25
_cell_volume                     2496.9(5)
_computing_cell_refinement       'APEX2 (Bruker AXS, 2006)'
_computing_data_collection       'APEX2 (Bruker AXS, 2006)'
_computing_data_reduction        'SAINT (Bruker AXS, 2004)'
_computing_molecular_graphics    'XSHEL (Bruker AXS,2002)'
_computing_publication_material  'XCIF (Bruker AXS, 2001)'
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1997)'
_diffrn_ambient_temperature      120.0(1)
_diffrn_detector_area_resol_mean 8.333
_diffrn_measured_fraction_theta_full 0.996
_diffrn_measured_fraction_theta_max 0.996
_diffrn_measurement_device_type  'Bruker APEXII CCD area detector'
_diffrn_measurement_method       'phi and omega scans'
_diffrn_radiation_monochromator  'Bruker Helios multilayer confocal mirror'
_diffrn_radiation_source         'Bruker TXS fine-focus rotating anode'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0893
_diffrn_reflns_av_sigmaI/netI    0.0457
_diffrn_reflns_limit_h_max       19
_diffrn_reflns_limit_h_min       -19
_diffrn_reflns_limit_k_max       15
_diffrn_reflns_limit_k_min       -15
_diffrn_reflns_limit_l_max       19
_diffrn_reflns_limit_l_min       -19
_diffrn_reflns_number            27705
_diffrn_reflns_theta_full        27.48
_diffrn_reflns_theta_max         27.48
_diffrn_reflns_theta_min         1.44
_exptl_absorpt_coefficient_mu    0.192
_exptl_absorpt_correction_T_max  0.9557
_exptl_absorpt_correction_T_min  0.9337
_exptl_absorpt_correction_type   empirical
_exptl_absorpt_process_details
; 
SADABS Sheldrick 1996 
;
_exptl_crystal_colour            Purple
_exptl_crystal_density_diffrn    1.013
_exptl_crystal_description       cubic
_exptl_crystal_F_000             848
_exptl_crystal_size_max          0.36
_exptl_crystal_size_mid          0.31
_exptl_crystal_size_min          0.24
_refine_diff_density_max         0.825
_refine_diff_density_min         -0.792
_refine_diff_density_rms         0.057
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.049
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     221
_refine_ls_number_reflns         5710
_refine_ls_number_restraints     15
_refine_ls_restrained_S_all      1.075
_refine_ls_R_factor_all          0.0449
_refine_ls_R_factor_gt           0.0420
_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^)+(0.0511P)^2^+1.5438P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1131
_refine_ls_wR_factor_ref         0.1160
_reflns_number_gt                5248
_reflns_number_total             5710
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            ja2014746_si_001.cif
_cod_data_source_block           para-Si2quinodimethane
_cod_original_sg_symbol_H-M      'P 1 21/c 1 '
_cod_database_code               4106000