Contraction and Expansion of the Silicon Scaffold of Stable Si6R6 Isomers
Kai Abersfelder; Adam Russell; Henry S. Rzepa; Andrew J. P. White; Peter R. Haycock; David Scheschkewitz; Journal of the American Chemical Society 134 (2012) 16008–16016; doi:10.1021/ja307344f

data_4118685
_publ_section_title
;
 Contraction and Expansion of the Silicon Scaffold of Stable Si6R6 Isomers
;
_journal_name_full               'Journal of the American Chemical Society'
_journal_page_first              16008
_journal_page_last               16016
_journal_paper_doi               10.1021/ja307344f
_journal_volume                  134
_journal_year                    2012
_chemical_formula_moiety         'C90 H138 Si6'
_chemical_formula_sum            'C90 H138 Si6'
_chemical_formula_weight         1388.54
_space_group_IT_number           2
_symmetry_cell_setting           triclinic
_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-97
_cell_angle_alpha                73.888(3)
_cell_angle_beta                 83.705(3)
_cell_angle_gamma                85.808(3)
_cell_formula_units_Z            2
_cell_length_a                   14.9868(5)
_cell_length_b                   17.1992(6)
_cell_length_c                   17.4782(6)
_cell_measurement_reflns_used    12386
_cell_measurement_temperature    173(2)
_cell_measurement_theta_max      72.3186
_cell_measurement_theta_min      2.6405
_cell_volume                     4297.8(3)
_computing_cell_refinement       'CrysAlis RED, Oxford Diffraction Ltd'
_computing_data_collection       'CrysAlis CCD, Oxford Diffraction Ltd'
_computing_data_reduction        'CrysAlis RED, Oxford Diffraction Ltd'
_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      173(2)
_diffrn_detector_area_resol_mean 8.2556
_diffrn_measured_fraction_theta_full 0.986
_diffrn_measured_fraction_theta_max 0.947
_diffrn_measurement_device_type  'OD Xcalibur PX Ultra'
_diffrn_measurement_method       'omega scans'
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'Enhance Ultra (Cu) X-ray Source'
_diffrn_radiation_type           CuK\a
_diffrn_radiation_wavelength     1.54184
_diffrn_reflns_av_R_equivalents  0.0441
_diffrn_reflns_av_sigmaI/netI    0.0703
_diffrn_reflns_limit_h_max       15
_diffrn_reflns_limit_h_min       -18
_diffrn_reflns_limit_k_max       20
_diffrn_reflns_limit_k_min       -20
_diffrn_reflns_limit_l_max       21
_diffrn_reflns_limit_l_min       -15
_diffrn_reflns_number            27589
_diffrn_reflns_theta_full        68.00
_diffrn_reflns_theta_max         72.72
_diffrn_reflns_theta_min         2.64
_diffrn_standards_number         0
_exptl_absorpt_coefficient_mu    1.210
_exptl_absorpt_correction_T_max  1.00000
_exptl_absorpt_correction_T_min  0.47371
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details
; 
CrysAlis RED, Oxford Diffraction Ltd., 
Version 1.171.33.32 (release 27-01-2009 CrysAlis171 .NET) 
(compiled Jan 27 2009,14:17:37) 
empirical absorption correction using spherical harmonics, 
implemented in SCALE3 ABSPACK scaling algorithm. 
;
_exptl_crystal_colour            Yellow
_exptl_crystal_density_diffrn    1.073
_exptl_crystal_description       prisms
_exptl_crystal_F_000             1524
_exptl_crystal_size_max          0.24
_exptl_crystal_size_mid          0.20
_exptl_crystal_size_min          0.07
_refine_diff_density_max         1.388
_refine_diff_density_min         -0.518
_refine_diff_density_rms         0.105
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.047
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     878
_refine_ls_number_reflns         16223
_refine_ls_number_restraints     25
_refine_ls_restrained_S_all      1.050
_refine_ls_R_factor_all          0.1160
_refine_ls_R_factor_gt           0.0871
_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^)+(0.1598P)^2^+6.8375P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.2762
_refine_ls_wR_factor_ref         0.2868
_reflns_number_gt                11304
_reflns_number_total             16223
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            ja307344f_si_002_2.cif
_cod_data_source_block           8a
_cod_database_code               4118685