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_4115396
_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            'C27 H63 Ge Li Si3'
_chemical_formula_weight         551.57
_chemical_name_systematic
;
  Tris[di-tert-butyl(methyl)silyl]germyllithium
;
_space_group_IT_number           33
_symmetry_cell_setting           orthorhombic
_symmetry_space_group_name_Hall  'P 2c -2n'
_symmetry_space_group_name_H-M   'P n a 21'
_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                90.00
_cell_formula_units_Z            4
_cell_length_a                   16.9060(2)
_cell_length_b                   11.4130(6)
_cell_length_c                   17.5190(6)
_cell_measurement_reflns_used    33448
_cell_measurement_temperature    120
_cell_measurement_theta_max      27.91
_cell_measurement_theta_min      2.13
_cell_volume                     3380.3(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 0.996
_diffrn_measured_fraction_theta_max 0.996
_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  0.060
_diffrn_reflns_av_sigmaI/netI    0.0363
_diffrn_reflns_limit_h_max       22
_diffrn_reflns_limit_h_min       0
_diffrn_reflns_limit_k_max       15
_diffrn_reflns_limit_k_min       0
_diffrn_reflns_limit_l_max       0
_diffrn_reflns_limit_l_min       -23
_diffrn_reflns_number            33448
_diffrn_reflns_theta_full        27.91
_diffrn_reflns_theta_max         27.91
_diffrn_reflns_theta_min         2.13
_exptl_absorpt_coefficient_mu    1.025
_exptl_absorpt_correction_type   none
_exptl_crystal_colour            Colorless
_exptl_crystal_density_diffrn    1.084
_exptl_crystal_description       cubic
_exptl_crystal_F_000             1208
_exptl_crystal_size_max          0.15
_exptl_crystal_size_mid          0.10
_exptl_crystal_size_min          0.10
_refine_diff_density_max         0.599
_refine_diff_density_min         -0.753
_refine_diff_density_rms         0.078
_refine_ls_abs_structure_details 'Flack H D (1983), Acta Cryst. A39, 876-881'
_refine_ls_abs_structure_Flack   0.117(10)
_refine_ls_extinction_coef       0.0103(8)
_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   1.060
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     290
_refine_ls_number_reflns         4163
_refine_ls_number_restraints     1
_refine_ls_restrained_S_all      1.060
_refine_ls_R_factor_all          0.0399
_refine_ls_R_factor_gt           0.0354
_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^)+(0.0641P)^2^+0.1310P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0922
_refine_ls_wR_factor_ref         0.0948
_reflns_number_gt                3825
_reflns_number_total             4163
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            ja021142r_2.cif
_cod_data_source_block           shelxl
_cod_original_sg_symbol_H-M      'P n a 21 '
_cod_database_code               4115396