Crystal structures of 2-bromo-1,1,1,3,3,3-hexamethyl-2-(trimethylsilyl)trisilane and 2-bromo-1,1,1,3,3,3-hexaisopropyl-2-(triisopropylsilyl)trisilane
Gulotty, Eva M.; Staples, Richard J.; Biros, Shannon M.; Gaspar, Peter P.; Rath, Nigam P.; Winchester, William R.; Acta Crystallographica Section E 74 (2018) 1142–1146; doi:10.1107/S2056989018009696

data_2242574
_publ_section_title
;
 Crystal structures of
 2-bromo-1,1,1,3,3,3-hexamethyl-2-(trimethylsilyl)trisilane and
 2-bromo-1,1,1,3,3,3-hexaisopropyl-2-(triisopropylsilyl)trisilane
;
_journal_issue                   8
_journal_name_full               'Acta Crystallographica Section E'
_journal_page_first              1142
_journal_page_last               1146
_journal_paper_doi               10.1107/S2056989018009696
_journal_volume                  74
_journal_year                    2018
_chemical_formula_iupac          'C27 H63 Br Si4'
_chemical_formula_moiety         'C27 H63 Br Si4'
_chemical_formula_sum            'C27 H63 Br Si4'
_chemical_formula_weight         580.04
_chemical_name_systematic
;
2-Bromo-1,1,1,3,3,3-hexaisopropyl-2-(triisopropylsilyl)trisilane
;
_space_group_crystal_system      triclinic
_space_group_IT_number           2
_space_group_name_Hall           '-P 1'
_space_group_name_H-M_alt        'P -1'
_symmetry_space_group_name_Hall  '-P 1'
_symmetry_space_group_name_H-M   'P -1'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_audit_creation_method           SHELXL-2014/7
_cell_angle_alpha                92.565(4)
_cell_angle_beta                 90.527(4)
_cell_angle_gamma                108.718(4)
_cell_formula_units_Z            2
_cell_length_a                   8.4412(4)
_cell_length_b                   11.1336(6)
_cell_length_c                   18.8477(10)
_cell_measurement_reflns_used    8192
_cell_measurement_temperature    173(2)
_cell_measurement_theta_max      26.0
_cell_measurement_theta_min      2.0
_cell_volume                     1675.44(15)
_computing_cell_refinement
;
SAINT (Bruker, 2014)
;
_computing_data_collection
;
SMART (Bruker, 2014)
;
_computing_data_reduction
;
SAINT (Bruker, 2014)
;
_computing_molecular_graphics
;
SHELXTL (Sheldrick, 2008)
;
_computing_publication_material
;
SHELXTL (Sheldrick, 2008)
;
_computing_structure_refinement
;
SHELXL2014 (Sheldrick, 2015b)
;
_computing_structure_solution
;
SHELXT2013 (Sheldrick, 2015a)
;
_diffrn_ambient_temperature      173(2)
_diffrn_detector_area_resol_mean 8
_diffrn_measured_fraction_theta_full 0.997
_diffrn_measured_fraction_theta_max 0.978
_diffrn_measurement_device_type  'Bruker SMART APEX CCD area detector'
_diffrn_measurement_method       '\w and \f scans'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0573
_diffrn_reflns_limit_h_max       10
_diffrn_reflns_limit_h_min       -10
_diffrn_reflns_limit_k_max       13
_diffrn_reflns_limit_k_min       -13
_diffrn_reflns_limit_l_max       23
_diffrn_reflns_limit_l_min       -23
_diffrn_reflns_number            21505
_diffrn_reflns_theta_full        25.242
_diffrn_reflns_theta_max         26.254
_diffrn_reflns_theta_min         1.082
_exptl_absorpt_coefficient_mu    1.383
_exptl_absorpt_correction_T_max  0.6744
_exptl_absorpt_correction_T_min  0.5535
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details
;
(SADABS; Bruker, 2014)
;
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.150
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       needles
_exptl_crystal_F_000             632
_exptl_crystal_size_max          0.380
_exptl_crystal_size_mid          0.100
_exptl_crystal_size_min          0.020
_refine_diff_density_max         0.357
_refine_diff_density_min         -0.275
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.010
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     307
_refine_ls_number_reflns         6628
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.010
_refine_ls_R_factor_all          0.0705
_refine_ls_R_factor_gt           0.0371
_refine_ls_shift/su_max          0.001
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'w=1/[\s^2^(Fo^2^)+(0.0274P)^2^+0.3128P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0661
_refine_ls_wR_factor_ref         0.0751
_reflns_number_gt                4752
_reflns_number_total             6628
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            su5451sup1.cif
_cod_data_source_block           II
_cod_database_code               2242574
_cod_database_fobs_code          2242574
_shelx_estimated_absorpt_t_min   0.621
_shelx_estimated_absorpt_t_max   0.973
_shelx_hkl_checksum              92216
_shelx_res_checksum              62158