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_4115398
_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            'C168 H372 Ge4 Li4 O15 Si12'
_chemical_formula_weight         3287.86
_chemical_name_systematic
;
  Lithium tris[di-tert-butyl(methyl)silyl]germanide
;
_space_group_IT_number           161
_symmetry_cell_setting           trigonal
_symmetry_space_group_name_Hall  'R 3 -2"c'
_symmetry_space_group_name_H-M   'R 3 c :H'
_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                 90.00
_cell_angle_gamma                120.00
_cell_formula_units_Z            6
_cell_length_a                   33.1560(6)
_cell_length_b                   33.1560(6)
_cell_length_c                   32.8840(5)
_cell_measurement_reflns_used    107033
_cell_measurement_temperature    120
_cell_measurement_theta_max      27.88
_cell_measurement_theta_min      2.13
_cell_volume                     31306.9(9)
_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 0.999
_diffrn_measured_fraction_theta_max 0.999
_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  0.0900
_diffrn_reflns_av_sigmaI/netI    0.0494
_diffrn_reflns_limit_h_max       43
_diffrn_reflns_limit_h_min       0
_diffrn_reflns_limit_k_max       0
_diffrn_reflns_limit_k_min       -37
_diffrn_reflns_limit_l_max       43
_diffrn_reflns_limit_l_min       -43
_diffrn_reflns_number            107033
_diffrn_reflns_theta_full        27.88
_diffrn_reflns_theta_max         27.88
_diffrn_reflns_theta_min         2.13
_exptl_absorpt_coefficient_mu    0.688
_exptl_absorpt_correction_type   none
_exptl_crystal_colour            Yellow
_exptl_crystal_density_diffrn    1.046
_exptl_crystal_description       Cube
_exptl_crystal_F_000             10848
_exptl_crystal_size_max          0.25
_exptl_crystal_size_mid          0.25
_exptl_crystal_size_min          0.15
_refine_diff_density_max         5.472
_refine_diff_density_min         -0.901
_refine_diff_density_rms         0.127
_refine_ls_abs_structure_details 'Flack H D (1983), Acta Cryst. A39, 876-881'
_refine_ls_abs_structure_Flack   0.00
_refine_ls_extinction_coef       0.00085(6)
_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   1.047
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     611
_refine_ls_number_reflns         16164
_refine_ls_number_restraints     1
_refine_ls_restrained_S_all      1.047
_refine_ls_R_factor_all          0.0794
_refine_ls_R_factor_gt           0.0696
_refine_ls_shift/su_max          0.517
_refine_ls_shift/su_mean         0.023
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.1118P)^2^+98.0461P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1754
_refine_ls_wR_factor_ref         0.1842
_reflns_number_gt                14272
_reflns_number_total             16164
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            ja021142r_4.cif
_cod_data_source_block           shelxl
_cod_original_cell_volume        31306.8(9)
_cod_original_sg_symbol_H-M      'R 3 c '
_cod_database_code               4115398