The crystal structure of 1,6-di-tert-butyl-1,1,3,3,4,4,6,6-octamethyl-2,2,5,5-tetrakis (trimethylsilyl)hexasilane, C28H78Si10
Xiao, Xu-Qiong; Xu, Jun-Ting; Wu, Yinan; Wang, Qiong-Yan; Zeitschrift für Kristallographie - New Crystal Structures 234 (2019) 1195–1198; doi:10.1515/ncrs-2019-0321

data_8105976
_publ_section_title
;
 The crystal structure of
 1,6-di-tert-butyl-1,1,3,3,4,4,6,6-octamethyl-2,2,5,5-tetrakis
 (trimethylsilyl)hexasilane, C28H78Si10
;
_journal_issue                   6
_journal_name_full
'Zeitschrift f\"ur Kristallographie - New Crystal Structures'
_journal_page_first              1195
_journal_page_last               1198
_journal_paper_doi               10.1515/ncrs-2019-0321
_journal_volume                  234
_journal_year                    2019
_chemical_formula_moiety         'C28 H78 Si10'
_chemical_formula_sum            'C28 H78 Si10'
_chemical_formula_weight         695.80
_chemical_name_systematic
;
1,6-di-<i>tert</i>-butyl-1,1,3,3,4,4,6,6-octamethyl-2,2,5,5-tetrakis
(trimethylsilyl)hexasilane
;
_space_group_crystal_system      monoclinic
_space_group_IT_number           7
_space_group_name_Hall           'P -2yac'
_space_group_name_H-M_alt        'P 1 n 1'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     SHELXT
_atom_sites_solution_secondary   difmap
_audit_creation_method           SHELXL-2014/7
_cell_angle_alpha                90
_cell_angle_beta                 93.426(4)
_cell_angle_gamma                90
_cell_formula_units_Z            4
_cell_length_a                   21.413(4)
_cell_length_b                   9.8568(17)
_cell_length_c                   22.074(4)
_cell_measurement_reflns_used    4604
_cell_measurement_temperature    296(2)
_cell_measurement_theta_max      21.80
_cell_measurement_theta_min      2.26
_cell_volume                     4650.7(15)
_computing_cell_refinement       'Bruker SAINT'
_computing_data_collection       'Bruker APEX2'
_computing_data_reduction        'Bruker SAINT'
_computing_molecular_graphics    'Bruker SHELXTL'
_computing_publication_material  'Bruker SHELXTL'
_computing_structure_refinement  'SHELXL-2014/7 (Sheldrick, 2014)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 2008)'
_diffrn_ambient_temperature      296(2)
_diffrn_measured_fraction_theta_full 0.993
_diffrn_measured_fraction_theta_max 0.992
_diffrn_measurement_device_type  'Bruker APEX-II CCD'
_diffrn_measurement_method       '\w scans'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0555
_diffrn_reflns_av_unetI/netI     0.0928
_diffrn_reflns_Laue_measured_fraction_full 0.993
_diffrn_reflns_Laue_measured_fraction_max 0.992
_diffrn_reflns_limit_h_max       27
_diffrn_reflns_limit_h_min       -27
_diffrn_reflns_limit_k_max       12
_diffrn_reflns_limit_k_min       -12
_diffrn_reflns_limit_l_max       24
_diffrn_reflns_limit_l_min       -28
_diffrn_reflns_number            29235
_diffrn_reflns_point_group_measured_fraction_full 0.742
_diffrn_reflns_point_group_measured_fraction_max 0.728
_diffrn_reflns_theta_full        25.242
_diffrn_reflns_theta_max         27.459
_diffrn_reflns_theta_min         1.287
_exptl_absorpt_coefficient_mu    0.299
_exptl_absorpt_correction_T_max  0.7456
_exptl_absorpt_correction_T_min  0.6623
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details
;
SADABS-2008/1 (Bruker,2008) was used for absorption correction. 
wR2(int) was 0.0610 before and 0.0514 after correction. 
The Ratio of minimum to maximum transmission is 0.8883. 
The \l/2 correction factor is 0.0015.'
;
_exptl_crystal_colour            colorless
_exptl_crystal_density_diffrn    0.994
_exptl_crystal_description       prism
_exptl_crystal_F_000             1544
_exptl_crystal_size_max          0.250
_exptl_crystal_size_mid          0.200
_exptl_crystal_size_min          0.200
_refine_diff_density_max         0.796
_refine_diff_density_min         -0.369
_refine_diff_density_rms         0.066
_refine_ls_abs_structure_details
; 
 Flack x determined using 2360 quotients [(I+)-(I-)]/[(I+)+(I-)] 
 (Parsons, Flack and Wagner, Acta Cryst. B69 (2013) 249-259). 
;
_refine_ls_abs_structure_Flack   0.40(10)
_refine_ls_extinction_coef       .
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   0.928
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     737
_refine_ls_number_reflns         15502
_refine_ls_number_restraints     2
_refine_ls_restrained_S_all      0.927
_refine_ls_R_factor_all          0.1139
_refine_ls_R_factor_gt           0.0613
_refine_ls_shift/su_max          0.025
_refine_ls_shift/su_mean         0.001
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'w=1/[\s^2^(Fo^2^)+(0.1000P)^2^] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1386
_refine_ls_wR_factor_ref         0.1750
_reflns_Friedel_coverage         0.467
_reflns_Friedel_fraction_full    0.490
_reflns_Friedel_fraction_max     0.464
_reflns_number_gt                9548
_reflns_number_total             15502
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            suppl_ncrs-2019-0321_suppl.cif
_cod_data_source_block           1
_cod_original_cell_volume        4650.6(14)
_cod_original_sg_symbol_H-M      'P n'
_cod_database_code               8105976
_shelx_shelxl_version_number     2014/7
_shelx_estimated_absorpt_t_min   0.929
_shelx_estimated_absorpt_t_max   0.943
_shelx_res_checksum              95951
_shelx_hkl_checksum              98104