A lithium complex of a bis(amido)bis(imido)silicate dianion
Copsey, May C.; Balakrishna, Maravanji S.; Chivers, Tristram; Acta Crystallographica Section E 62 (2006) m1683–m1685; doi:10.1107/S1600536806022161

data_2209440
_publ_section_title
;
 A lithium complex of a bis(amido)bis(imido)silicate dianion
;
_journal_coeditor_code           CF2034
_journal_issue                   7
_journal_name_full               'Acta Crystallographica Section E'
_journal_page_first              m1683
_journal_page_last               m1685
_journal_paper_doi               10.1107/S1600536806022161
_journal_volume                  62
_journal_year                    2006
_chemical_formula_iupac          '[Li6 (C16 H38 N4 Si)2 Cl2 (C4 H8 O)4]'
_chemical_formula_moiety         'C48 H108 Cl2 Li6 N8 O4 Si2'
_chemical_formula_sum            'C48 H108 Cl2 Li6 N8 O4 Si2'
_chemical_formula_weight         1030.14
_chemical_name_systematic
;
bis[\m~3~bis(<i>tert</i>-butylamido)bis(<i>tert</i>-butylimido)silyl]
di-\m~3~-chloro-tetratetrahydrofuranhexalithium(I)
;
_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                 95.40(3)
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   19.405(4)
_cell_length_b                   10.632(2)
_cell_length_c                   30.693(6)
_cell_measurement_reflns_used    5541
_cell_measurement_temperature    173(2)
_cell_measurement_theta_max      27.5
_cell_measurement_theta_min      3.53
_cell_volume                     6304(2)
_computing_cell_refinement       'DENZO (Otwinowski & Minor, 1997)'
_computing_data_collection       'COLLECT (Hooft, 1998)'
_computing_data_reduction        DENZO
_computing_molecular_graphics    SHELXTL
_computing_publication_material  SHELXTL
_computing_structure_refinement  SHELXTL
_computing_structure_solution    'SHELXTL (Bruker, 2000)'
_diffrn_ambient_temperature      173(2)
_diffrn_measured_fraction_theta_full 0.993
_diffrn_measured_fraction_theta_max 0.993
_diffrn_measurement_device_type  'Nonius KappaCCD'
_diffrn_measurement_method       '\f and \w'
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'fine-focus sealed tube'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0472
_diffrn_reflns_av_sigmaI/netI    0.0581
_diffrn_reflns_limit_h_max       23
_diffrn_reflns_limit_h_min       -23
_diffrn_reflns_limit_k_max       12
_diffrn_reflns_limit_k_min       -12
_diffrn_reflns_limit_l_max       36
_diffrn_reflns_limit_l_min       -36
_diffrn_reflns_number            10599
_diffrn_reflns_theta_full        25.03
_diffrn_reflns_theta_max         25.03
_diffrn_reflns_theta_min         3.53
_diffrn_standards_number         0
_exptl_absorpt_coefficient_mu    0.184
_exptl_absorpt_correction_T_max  0.991
_exptl_absorpt_correction_T_min  0.964
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   '(SCALEPACK; Otwinowski & Minor, 1997)'
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.085
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       plate
_exptl_crystal_F_000             2256
_exptl_crystal_size_max          0.20
_exptl_crystal_size_mid          0.15
_exptl_crystal_size_min          0.05
_refine_diff_density_max         0.279
_refine_diff_density_min         -0.284
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.037
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     355
_refine_ls_number_reflns         5541
_refine_ls_number_restraints     20
_refine_ls_restrained_S_all      1.054
_refine_ls_R_factor_all          0.0976
_refine_ls_R_factor_gt           0.0583
_refine_ls_shift/su_max          0.008
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0557P)^2^+10.6595P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1302
_refine_ls_wR_factor_ref         0.1483
_reflns_number_gt                3720
_reflns_number_total             5541
_reflns_threshold_expression     I>2\s(I)
_cod_data_source_file            cf2034.cif
_cod_data_source_block           I
_cod_original_sg_symbol_H-M      'C 2/c'
_cod_database_code               2209440
_cod_database_fobs_code          2209440