A Free Silylium Ion: A Cyclotetrasilenylium Ion with Allylic Character
Inoue, Shigeyoshi; Ichinohe, Masaaki; Yamaguchi, Torahiko; Sekiguchi, Akira; Organometallics 27 (2008) 6056–; doi:10.1021/om800912v

data_4083513
_publ_section_title
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 A Free Silylium Ion: A Cyclotetrasilenylium Ion with Allylic Character
;
_journal_issue                   23
_journal_name_full               Organometallics
_journal_page_first              6056
_journal_paper_doi               10.1021/om800912v
_journal_volume                  27
_journal_year                    2008
_chemical_formula_sum            'C52 H60 B F20 Si5'
_chemical_formula_weight         1216.26
_chemical_name_systematic
; 
 1,3,4,4-Tetra-tert-butyl-2-(di-tert-butylmethylsilyl)-
 cyclotetrasilenylium Tetrakis(pentafluorophenyl)borate
;
_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                 90.844(2)
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   10.8810(4)
_cell_length_b                   17.2870(3)
_cell_length_c                   31.3220(10)
_cell_measurement_reflns_used    58614
_cell_measurement_temperature    150.0(1)
_cell_measurement_theta_max      28.15
_cell_measurement_theta_min      2.00
_cell_volume                     5891.0(3)
_computing_cell_refinement       'HKL scalepack'
_computing_data_collection       'MacScience Xpress'
_computing_data_reduction        Denzo
_computing_molecular_graphics    ORTEP
_computing_publication_material  CIFTAB
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    SIR92
_diffrn_ambient_temperature      150.0(1)
_diffrn_measured_fraction_theta_full 0.980
_diffrn_measured_fraction_theta_max 0.980
_diffrn_measurement_device       'MacScience DIP2030 Image plate'
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'rotating anode'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71070
_diffrn_reflns_av_R_equivalents  0.0380
_diffrn_reflns_av_sigmaI/netI    0.0400
_diffrn_reflns_limit_h_max       14
_diffrn_reflns_limit_h_min       0
_diffrn_reflns_limit_k_max       22
_diffrn_reflns_limit_k_min       0
_diffrn_reflns_limit_l_max       41
_diffrn_reflns_limit_l_min       -41
_diffrn_reflns_number            58614
_diffrn_reflns_theta_full        28.02
_diffrn_reflns_theta_max         28.02
_diffrn_reflns_theta_min         2.28
_exptl_absorpt_coefficient_mu    0.219
_exptl_absorpt_correction_type   none
_exptl_crystal_colour            Yellow
_exptl_crystal_density_diffrn    1.371
_exptl_crystal_density_meas      ?
_exptl_crystal_description       Cube
_exptl_crystal_F_000             2508
_exptl_crystal_size_max          0.4
_exptl_crystal_size_mid          0.05
_exptl_crystal_size_min          0.05
_refine_diff_density_max         2.174
_refine_diff_density_min         -0.668
_refine_diff_density_rms         0.085
_refine_ls_extinction_coef       0.0049(7)
_refine_ls_extinction_expression Fc^*^=kFc[1+0.001xFc^2^\l^3^/sin(2\q)]^-1/4^
_refine_ls_extinction_method     SHELXL
_refine_ls_goodness_of_fit_ref   1.090
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     751
_refine_ls_number_reflns         13960
_refine_ls_number_restraints     89
_refine_ls_restrained_S_all      1.099
_refine_ls_R_factor_all          0.0826
_refine_ls_R_factor_gt           0.0647
_refine_ls_shift/su_max          0.003
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.1334P)^2^+1.9329P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1971
_refine_ls_wR_factor_ref         0.2124
_reflns_number_gt                10389
_reflns_number_total             13960
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            om800912v_si_002.cif
_cod_data_source_block           shelxl
_cod_depositor_comments
;
The following automatic conversions were performed:

'_symmetry_cell_setting' value 'Monoclinic' changed to 'monoclinic'
according to
/usr/data/users/saulius/automatic-downloads/retrospective/ACS/lib/dictionaries/cif_core.dic
dictionary named 'cif_core.dic' version 2.4.2 from 2011-04-26.

Automatic conversion script
Id: cif_fix_values 2281 2013-09-26 08:29:07Z andrius 

The following automatic conversions were performed:

'_exptl_crystal_density_meas' value 'not measured' was changed to '?'
- the value is perceived as not measured.

Automatic conversion script
Id: cif_fix_values 3008 2015-01-20 13:52:24Z robertas 
;
_cod_original_sg_symbol_H-M      'P 21/c        '
_cod_database_code               4083513