Isolable Alkali-Metal-Substituted Silyl Radicals (tBu2MeSi)2SiM (M = Li, Na, K): Electronically and Sterically Accessible Planar Silyl Radicals
Inoue, Shigeyoshi; Ichinohe, Masaaki; Sekiguchi, Akira; Organometallics 27 (2008) 1358–; doi:10.1021/om8000185

data_4083497
_publ_section_title
;
 Isolable Alkali-Metal-Substituted Silyl Radicals (tBu2MeSi)2SiM (M = Li,
 Na, K): Electronically and Sterically Accessible Planar Silyl Radicals
;
_journal_issue                   7
_journal_name_full               Organometallics
_journal_page_first              1358
_journal_paper_doi               10.1021/om8000185
_journal_volume                  27
_journal_year                    2008
_chemical_formula_sum            'C44 H100 Li2 O2 Si6'
_chemical_formula_weight         843.66
_chemical_name_systematic
; 
 Bis{bis(di-tert-butylmethylsilyl)[(tetrahydrofuran)lithio]silyl}
;
_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                 94.838(4)
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   15.0480(6)
_cell_length_b                   16.0300(14)
_cell_length_c                   23.1830(18)
_cell_measurement_reflns_used    39247
_cell_measurement_temperature    120.0(1)
_cell_measurement_theta_max      25.22
_cell_measurement_theta_min      2.11
_cell_volume                     5572.3(7)
_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      120.0(1)
_diffrn_measured_fraction_theta_full 0.937
_diffrn_measured_fraction_theta_max 0.937
_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  0.0660
_diffrn_reflns_av_sigmaI/netI    0.0651
_diffrn_reflns_limit_h_max       17
_diffrn_reflns_limit_h_min       0
_diffrn_reflns_limit_k_max       19
_diffrn_reflns_limit_k_min       0
_diffrn_reflns_limit_l_max       27
_diffrn_reflns_limit_l_min       -27
_diffrn_reflns_number            39247
_diffrn_reflns_theta_full        25.22
_diffrn_reflns_theta_max         25.22
_diffrn_reflns_theta_min         2.11
_exptl_absorpt_coefficient_mu    0.179
_exptl_absorpt_correction_type   none
_exptl_crystal_colour            'Pale orange'
_exptl_crystal_density_diffrn    1.006
_exptl_crystal_density_meas      ?
_exptl_crystal_description       Needle
_exptl_crystal_F_000             1880
_exptl_crystal_size_max          0.4
_exptl_crystal_size_mid          0.15
_exptl_crystal_size_min          0.1
_refine_diff_density_max         0.374
_refine_diff_density_min         -0.379
_refine_diff_density_rms         0.076
_refine_ls_extinction_coef       0.0041(4)
_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   0.956
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     488
_refine_ls_number_reflns         9417
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      0.956
_refine_ls_R_factor_all          0.0889
_refine_ls_R_factor_gt           0.0514
_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^)+(0.0892P)^2^+0.0000P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1322
_refine_ls_wR_factor_ref         0.1538
_reflns_number_gt                5968
_reflns_number_total             9417
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            om8000185-file003.cif
_cod_data_source_block           '[(tBu2MeSi)2SiLi(THF)]2'
_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               4083497