A low-temperature modification of hexa-<i>tert</i>-butyldisilane and a new polymorph of 1,1,2,2-tetra-<i>tert</i>-butyl-1,2-diphenyldisilane
Scholz, Stefan; Lerner, Hans-Wolfram; Bats, Jan W.; Acta Crystallographica Section C 70 (2014) 697–701; doi:10.1107/S2053229614013503

data_2019600
_publ_section_title
;
 A low-temperature modification of hexa-<i>tert</i>-butyldisilane and a
 new polymorph of 1,1,2,2-tetra-<i>tert</i>-butyl-1,2-diphenyldisilane
;
_journal_issue                   7
_journal_name_full               'Acta Crystallographica Section C'
_journal_page_first              697
_journal_page_last               701
_journal_paper_doi               10.1107/S2053229614013503
_journal_volume                  70
_journal_year                    2014
_chemical_formula_iupac          'C24 H54 Si2'
_chemical_formula_moiety         'C24 H54 Si2'
_chemical_formula_sum            'C24 H54 Si2'
_chemical_formula_weight         398.85
_chemical_name_systematic
;
Hexa-<i>tert</i>-butyldisilane
;
_space_group_IT_number           61
_symmetry_cell_setting           orthorhombic
_symmetry_space_group_name_Hall  '-P 2ac 2ab'
_symmetry_space_group_name_H-M   'P b c a'
_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                 90.00
_cell_angle_gamma                90.00
_cell_formula_units_Z            8
_cell_length_a                   11.2923(8)
_cell_length_b                   29.204(3)
_cell_length_c                   15.8321(16)
_cell_measurement_reflns_used    371
_cell_measurement_temperature    147(2)
_cell_measurement_theta_max      26
_cell_measurement_theta_min      3
_cell_volume                     5221.1(8)
_computing_cell_refinement       'SMART (Siemens, 1995)'
_computing_data_collection       'SMART (Siemens, 1995)'
_computing_data_reduction        'SAINT (Siemens, 1995)'
_computing_molecular_graphics    'SHELXTL (Sheldrick, 2008)'
_computing_publication_material  'SHELXL97 (Sheldrick, 2008)'
_computing_structure_refinement  'SHELXL97 (Sheldrick, 2008)'
_computing_structure_solution    'SHELXS97 (Sheldrick, 2008)'
_diffrn_ambient_temperature      147(2)
_diffrn_measured_fraction_theta_full 0.983
_diffrn_measured_fraction_theta_max 0.983
_diffrn_measurement_device_type  'Siemens SMART 1K CCD'
_diffrn_measurement_method       \w
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'normal-focus sealed tube'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0559
_diffrn_reflns_av_sigmaI/netI    0.0481
_diffrn_reflns_limit_h_max       15
_diffrn_reflns_limit_h_min       -15
_diffrn_reflns_limit_k_max       41
_diffrn_reflns_limit_k_min       -41
_diffrn_reflns_limit_l_max       20
_diffrn_reflns_limit_l_min       -21
_diffrn_reflns_number            58910
_diffrn_reflns_theta_full        30.00
_diffrn_reflns_theta_max         30.00
_diffrn_reflns_theta_min         2.32
_diffrn_standards_decay_%        0.0
_diffrn_standards_interval_time  1200
_diffrn_standards_number         689
_exptl_absorpt_coefficient_mu    0.142
_exptl_absorpt_correction_T_max  0.980
_exptl_absorpt_correction_T_min  0.856
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   '(SADABS; Sheldrick, 2000)'
_exptl_crystal_colour            colorless
_exptl_crystal_density_diffrn    1.015
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       rod
_exptl_crystal_F_000             1808
_exptl_crystal_size_max          0.75
_exptl_crystal_size_mid          0.27
_exptl_crystal_size_min          0.14
_refine_diff_density_max         0.338
_refine_diff_density_min         -0.237
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.046
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     253
_refine_ls_number_reflns         7483
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.046
_refine_ls_R_factor_all          0.0921
_refine_ls_R_factor_gt           0.0483
_refine_ls_shift/su_max          0.001
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.05P)^2^+0.8P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1020
_refine_ls_wR_factor_ref         0.1157
_reflns_number_gt                4986
_reflns_number_total             7483
_reflns_threshold_expression     I>2\s(I)
_cod_data_source_file            fg3323sup1.cif
_cod_data_source_block           I
_cod_depositor_comments
'Adding full bibliography for 2019600--2019601.cif.'
_cod_database_code               2019600
_cod_database_fobs_code          2019600