An isolable disilyne anion radical and a new route to the disilenide ion upon reduction of a disilyne.
Kinjo, Rei; Ichinohe, Masaaki; Sekiguchi, Akira; Journal of the American Chemical Society 129 (2007) 26–27; doi:10.1021/ja066762x

data_4101763
_publ_section_title
;
 An isolable disilyne anion radical and a new route to the disilenide ion
 upon reduction of a disilyne.
;
_journal_issue                   1
_journal_name_full               'Journal of the American Chemical Society'
_journal_page_first              26
_journal_page_last               27
_journal_paper_doi               10.1021/ja066762x
_journal_volume                  129
_journal_year                    2007
_chemical_formula_sum            'C50 H130 K O8 Si12'
_chemical_formula_weight         1235.72
_chemical_name_systematic
; 
 1,1,4,4-tetrakis[bis(trimethylsilyl)methyl]-1,4-diisopropyl-
 2-tetrasilyne anion radical 
;
_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                 93.542(4)
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   11.1710(8)
_cell_length_b                   22.1790(12)
_cell_length_c                   31.4580(19)
_cell_measurement_reflns_used    81605
_cell_measurement_temperature    120.0(1)
_cell_measurement_theta_max      27.98
_cell_measurement_theta_min      2.11
_cell_volume                     7779.2(8)
_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 0.962
_diffrn_measured_fraction_theta_max 0.962
_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  0.0650
_diffrn_reflns_av_sigmaI/netI    0.0729
_diffrn_reflns_limit_h_max       14
_diffrn_reflns_limit_h_min       0
_diffrn_reflns_limit_k_max       29
_diffrn_reflns_limit_k_min       0
_diffrn_reflns_limit_l_max       41
_diffrn_reflns_limit_l_min       -41
_diffrn_reflns_number            81605
_diffrn_reflns_theta_full        27.98
_diffrn_reflns_theta_max         27.98
_diffrn_reflns_theta_min         2.11
_exptl_absorpt_coefficient_mu    0.292
_exptl_absorpt_correction_type   none
_exptl_crystal_colour            'dark brown'
_exptl_crystal_density_diffrn    1.055
_exptl_crystal_density_meas      ?
_exptl_crystal_description       cube
_exptl_crystal_F_000             2724
_exptl_crystal_size_max          0.25
_exptl_crystal_size_mid          0.25
_exptl_crystal_size_min          0.20
_refine_diff_density_max         1.046
_refine_diff_density_min         -0.480
_refine_diff_density_rms         0.089
_refine_ls_extinction_coef       0.0021(3)
_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   0.984
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     641
_refine_ls_number_reflns         18045
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      0.984
_refine_ls_R_factor_all          0.1229
_refine_ls_R_factor_gt           0.0712
_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^)+(0.1269P)^2^+0.0000P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1798
_refine_ls_wR_factor_ref         0.2145
_reflns_number_gt                10421
_reflns_number_total             18045
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            ja066762xsi20060920_125208.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 the built-in table from CIF Core dictionary named
'cif_core.dic' version 2.4.1 from 2010-06-29.

Automatic conversion script
Id: cif_fix_values 1673 2011-04-08 12:14:43Z adriana 

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               4101763