Isomeric Metamorphosis: Si3E (E = S, Se, and Te) Bicyclo[1.1.0]butane and Cyclobutene
Vladimir Ya. Lee; Shogo Miyazaki; Hiroyuki Yasuda; Akira Sekiguchi; Journal of the American Chemical Society 130 (2008) 2758–2759; doi:10.1021/ja800111r

data_4107499
_publ_section_title
;
 Isomeric Metamorphosis: Si3E (E = S, Se, and Te) Bicyclo[1.1.0]butane and
 Cyclobutene
;
_journal_name_full               'Journal of the American Chemical Society'
_journal_page_first              2758
_journal_page_last               2759
_journal_paper_doi               10.1021/ja800111r
_journal_volume                  130
_journal_year                    2008
_chemical_formula_sum            'C36 H84 Se Si7'
_chemical_formula_weight         792.62
_chemical_name_systematic
;
 Si3Se-cyclobutene
;
_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                 123.580(2)
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   20.0070(7)
_cell_length_b                   12.2430(4)
_cell_length_c                   23.7230(7)
_cell_measurement_reflns_used    48800
_cell_measurement_temperature    150
_cell_measurement_theta_max      27.91
_cell_measurement_theta_min      2.06
_cell_volume                     4841.1(3)
_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      150
_diffrn_measured_fraction_theta_full 0.952
_diffrn_measured_fraction_theta_max 0.952
_diffrn_measurement_device_type  '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  0.043
_diffrn_reflns_av_sigmaI/netI    0.0370
_diffrn_reflns_limit_h_max       26
_diffrn_reflns_limit_h_min       0
_diffrn_reflns_limit_k_max       0
_diffrn_reflns_limit_k_min       -16
_diffrn_reflns_limit_l_max       25
_diffrn_reflns_limit_l_min       -31
_diffrn_reflns_number            48800
_diffrn_reflns_theta_full        27.92
_diffrn_reflns_theta_max         27.91
_diffrn_reflns_theta_min         2.06
_exptl_absorpt_coefficient_mu    0.971
_exptl_absorpt_correction_type   none
_exptl_crystal_colour            yellow
_exptl_crystal_density_diffrn    1.088
_exptl_crystal_description       blocks
_exptl_crystal_F_000             1728
_exptl_crystal_size_max          0.55
_exptl_crystal_size_mid          0.50
_exptl_crystal_size_min          0.30
_refine_diff_density_max         3.932
_refine_diff_density_min         -0.902
_refine_diff_density_rms         0.101
_refine_ls_extinction_coef       0.0080(7)
_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   1.051
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     398
_refine_ls_number_reflns         11032
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.051
_refine_ls_R_factor_all          0.0761
_refine_ls_R_factor_gt           0.0615
_refine_ls_shift/su_max          0.004
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.1113P)^2^+5.0374P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1705
_refine_ls_wR_factor_ref         0.1827
_reflns_number_gt                8758
_reflns_number_total             11032
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            ja800111r-file004.cif
_cod_data_source_block           shelxl
_cod_original_sg_symbol_H-M      'P 21/c '
_cod_database_code               4107499