Tetrasilatetrahedranide: A Silicon Cage Anion
Masaaki Ichinohe; Masafumi Toyoshima; Rei Kinjo; Akira Sekiguchi; Journal of the American Chemical Society 125 (2003) 13328–13329; doi:10.1021/ja0305050

data_4114305
_publ_section_title
;
 Tetrasilatetrahedranide: A Silicon Cage Anion
;
_journal_name_full               'Journal of the American Chemical Society'
_journal_page_first              13328
_journal_page_last               13329
_journal_paper_doi               10.1021/ja0305050
_journal_volume                  125
_journal_year                    2003
_chemical_formula_sum            'C59.5 H153 K O6 Si19'
_chemical_formula_weight         1537.61
_chemical_name_systematic
; 
 (18-crown-6)potassium tris{bis[bis(trimethylsilyl)methyl](methyl)silyl}
 tetrasilatetrahedranide
;
_space_group_IT_number           15
_symmetry_cell_setting           monoclinic
_symmetry_space_group_name_Hall  '-C 2yc'
_symmetry_space_group_name_H-M   'C 1 2/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                 121.573(2)
_cell_angle_gamma                90.00
_cell_formula_units_Z            8
_cell_length_a                   46.3770(18)
_cell_length_b                   16.8430(3)
_cell_length_c                   28.7790(11)
_cell_measurement_reflns_used    96893
_cell_measurement_temperature    120
_cell_measurement_theta_max      27.95
_cell_measurement_theta_min      2.06
_cell_volume                     19152.4(12)
_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    'SHELXS-97 (Sheldrick, 1990)'
_diffrn_ambient_temperature      120
_diffrn_measured_fraction_theta_full 0.988
_diffrn_measured_fraction_theta_max 0.988
_diffrn_measurement_device_type  '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  0.0870
_diffrn_reflns_av_sigmaI/netI    0.0851
_diffrn_reflns_limit_h_max       60
_diffrn_reflns_limit_h_min       0
_diffrn_reflns_limit_k_max       22
_diffrn_reflns_limit_k_min       0
_diffrn_reflns_limit_l_max       32
_diffrn_reflns_limit_l_min       -37
_diffrn_reflns_number            96893
_diffrn_reflns_theta_full        27.95
_diffrn_reflns_theta_max         27.95
_diffrn_reflns_theta_min         2.06
_exptl_absorpt_coefficient_mu    0.330
_exptl_absorpt_correction_type   none
_exptl_crystal_colour            Red
_exptl_crystal_density_diffrn    1.066
_exptl_crystal_description       cubic
_exptl_crystal_F_000             6480
_exptl_crystal_size_max          0.4
_exptl_crystal_size_mid          0.4
_exptl_crystal_size_min          0.4
_refine_diff_density_max         0.804
_refine_diff_density_min         -0.729
_refine_diff_density_rms         0.108
_refine_ls_extinction_coef       0.00196(10)
_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   0.994
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     772
_refine_ls_number_reflns         22757
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      0.994
_refine_ls_R_factor_all          0.1146
_refine_ls_R_factor_gt           0.0667
_refine_ls_shift/su_max          0.194
_refine_ls_shift/su_mean         0.004
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.1120P)^2^+0.0000P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1697
_refine_ls_wR_factor_ref         0.2004
_reflns_number_gt                13309
_reflns_number_total             22757
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            ja0305050.cif
_cod_data_source_block           shelxl
_cod_original_cell_volume        19152.4(11)
_cod_original_sg_symbol_H-M      'C 2/c'
_cod_database_code               4114305