Nearly Planar Nonsolvated Monomeric Silyl- and Germyllithiums as a Result of an Intramolecular CH-Li Agostic Interaction
Masaaki Nakamoto; Tomohide Fukawa; Vladimir Ya. Lee; Akira Sekiguchi; Journal of the American Chemical Society 124 (2002) 15160–15161; doi:10.1021/ja021142r

data_4115397
_publ_section_title
;
 Nearly Planar Nonsolvated Monomeric Silyl- and Germyllithiums as a Result
 of an Intramolecular CH-Li Agostic Interaction
;
_journal_name_full               'Journal of the American Chemical Society'
_journal_page_first              15160
_journal_page_last               15161
_journal_paper_doi               10.1021/ja021142r
_journal_volume                  124
_journal_year                    2002
_chemical_formula_sum            'C43 H95 Li O4 Si4'
_chemical_formula_weight         795.49
_chemical_name_systematic
;
  tris[di-tert-butyl(methyl)silyl]silyllithium (THF)4
;
_space_group_IT_number           14
_symmetry_cell_setting           monoclinic
_symmetry_space_group_name_Hall  '-P 2yn'
_symmetry_space_group_name_H-M   'P 1 21/n 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                 93.628(15)
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   14.829(5)
_cell_length_b                   20.776(6)
_cell_length_c                   16.806(3)
_cell_measurement_reflns_used    49025
_cell_measurement_temperature    120
_cell_measurement_theta_max      27.80
_cell_measurement_theta_min      2.03
_cell_volume                     5167(2)
_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
_diffrn_measured_fraction_theta_full 0.571
_diffrn_measured_fraction_theta_max 0.571
_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  0.184
_diffrn_reflns_av_sigmaI/netI    0.3723
_diffrn_reflns_limit_h_max       18
_diffrn_reflns_limit_h_min       0
_diffrn_reflns_limit_k_max       26
_diffrn_reflns_limit_k_min       0
_diffrn_reflns_limit_l_max       20
_diffrn_reflns_limit_l_min       -21
_diffrn_reflns_number            49025
_diffrn_reflns_theta_full        27.80
_diffrn_reflns_theta_max         27.80
_diffrn_reflns_theta_min         2.03
_exptl_absorpt_coefficient_mu    0.149
_exptl_absorpt_correction_type   none
_exptl_crystal_colour            Yellow
_exptl_crystal_density_diffrn    1.023
_exptl_crystal_description       Cube
_exptl_crystal_F_000             1776
_exptl_crystal_size_max          0.10
_exptl_crystal_size_mid          0.10
_exptl_crystal_size_min          0.10
_refine_diff_density_max         0.613
_refine_diff_density_min         -0.295
_refine_diff_density_rms         0.066
_refine_ls_extinction_coef       0.0020(5)
_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   0.771
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     470
_refine_ls_number_reflns         6992
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      0.771
_refine_ls_R_factor_all          0.2460
_refine_ls_R_factor_gt           0.0775
_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^)+(0.1021P)^2^+0.0000P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1735
_refine_ls_wR_factor_ref         0.2247
_reflns_number_gt                2139
_reflns_number_total             6992
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            ja021142r_3.cif
_cod_data_source_block           shelxl
_cod_original_cell_volume        5167(3)
_cod_original_sg_symbol_H-M      'P 21/n '
_cod_database_code               4115397