The First Halogen-Substituted Cyclotrigermenes: A Unique Halogen Walk over the Three-Membered Ring Skeleton and Facial Stereoselectivity in the Diels-Alder Reaction
Akira Sekiguchi; Yutaka Ishida; Norihisa Fukaya; Masaaki Ichinohe; Nozomi Takagi; Shigeru Nagase; Journal of the American Chemical Society 124 (2002) 1158–1159; doi:10.1021/ja012216m

data_4114620
_publ_section_title
;
 The First Halogen-Substituted Cyclotrigermenes: A Unique Halogen Walk
 over the Three-Membered Ring Skeleton and Facial Stereoselectivity in the
 Diels-Alder Reaction
;
_journal_name_full               'Journal of the American Chemical Society'
_journal_page_first              1158
_journal_page_last               1159
_journal_paper_doi               10.1021/ja012216m
_journal_volume                  124
_journal_year                    2002
_chemical_formula_sum            'C42 H91 Br Ge3 Si3'
_chemical_formula_weight         978.10
_chemical_name_systematic
;
  7-Bromo-3,4-dimethyl-1,6,7-tris(tri-tert-butylsilyl)-
  1,6,7-trigermabicyclo[4.1.0]hept-3-ene
;
_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                 116.379(2)
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   13.5110(5)
_cell_length_b                   31.017(1)
_cell_length_c                   13.3710(5)
_cell_measurement_reflns_used    44188
_cell_measurement_temperature    120
_cell_measurement_theta_max      27.90
_cell_measurement_theta_min      2.13
_cell_volume                     5019.9(3)
_computing_cell_refinement       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 0.880
_diffrn_measured_fraction_theta_max 0.880
_diffrn_measurement_device_type  'MacScience DIP2030 Image plate'
_diffrn_orient_matrix_type       X=UH
_diffrn_orient_matrix_UB_11      0.02676
_diffrn_orient_matrix_UB_12      0.04026
_diffrn_orient_matrix_UB_13      0.06801
_diffrn_orient_matrix_UB_21      -0.02903
_diffrn_orient_matrix_UB_22      -0.00355
_diffrn_orient_matrix_UB_23      0.01352
_diffrn_orient_matrix_UB_31      0.03337
_diffrn_orient_matrix_UB_32      -0.04658
_diffrn_orient_matrix_UB_33      0.05942
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'rotating anode'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71070
_diffrn_reflns_av_R_equivalents  0.0360
_diffrn_reflns_av_sigmaI/netI    0.0316
_diffrn_reflns_limit_h_max       17
_diffrn_reflns_limit_h_min       0
_diffrn_reflns_limit_k_max       40
_diffrn_reflns_limit_k_min       0
_diffrn_reflns_limit_l_max       15
_diffrn_reflns_limit_l_min       -17
_diffrn_reflns_number            44188
_diffrn_reflns_theta_full        27.90
_diffrn_reflns_theta_max         27.90
_diffrn_reflns_theta_min         2.13
_exptl_absorpt_coefficient_mu    2.678
_exptl_absorpt_correction_type   none
_exptl_crystal_colour            Yellow
_exptl_crystal_density_diffrn    1.294
_exptl_crystal_description       cubic
_exptl_crystal_F_000             2064
_exptl_crystal_size_max          0.4
_exptl_crystal_size_mid          0.3
_exptl_crystal_size_min          0.3
_refine_diff_density_max         1.245
_refine_diff_density_min         -0.683
_refine_diff_density_rms         0.090
_refine_ls_extinction_coef       0.00300(18)
_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   1.046
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     443
_refine_ls_number_reflns         10571
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.046
_refine_ls_R_factor_all          0.0457
_refine_ls_R_factor_gt           0.0376
_refine_ls_shift/su_max          0.012
_refine_ls_shift/su_mean         0.001
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0533P)^2^+5.7440P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0970
_refine_ls_wR_factor_ref         0.1015
_reflns_number_gt                9100
_reflns_number_total             10571
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            ja012216m_5.cif
_cod_data_source_block           shelxl
_cod_original_sg_symbol_H-M      'P 21/c '
_cod_database_code               4114620