Synthesis, Structure, and Chemistry of New, Mixed Group 14 and 16 Heterocycles: Nucleophile-Induced Ring Contraction of Mesocyclic Dications
Eric Block; Evgeny V. Dikarev; Richard S. Glass; Jin Jin; Bo Li; Xiaojie Li; Shao-Zhong Zhang; Journal of the American Chemical Society 128 (2006) 14949–14961; doi:10.1021/ja065037j

data_4111083
_publ_section_title
;
 Synthesis, Structure, and Chemistry of New, Mixed Group 14 and 16
 Heterocycles: Nucleophile-Induced Ring Contraction of Mesocyclic
 Dications
;
_journal_name_full               'Journal of the American Chemical Society'
_journal_page_first              14949
_journal_page_last               14961
_journal_paper_doi               10.1021/ja065037j
_journal_volume                  128
_journal_year                    2006
_chemical_formula_moiety         'Se2 (C H2)4 (Si (C H3)2)2'
_chemical_formula_sum            'C8 H20 Se2 Si2'
_chemical_formula_weight         330.34
_chemical_name_systematic
; 
 3,3,7,7-Tetramethyl-1,5-diselena-3,7-disilocane 
;
_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   difmap
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_audit_creation_method           SHELXL-97
_cell_angle_alpha                90.00
_cell_angle_beta                 99.6510(10)
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   7.3665(4)
_cell_length_b                   13.2789(7)
_cell_length_c                   14.1387(7)
_cell_measurement_reflns_used    8543
_cell_measurement_temperature    173(2)
_cell_measurement_theta_max      28.19
_cell_measurement_theta_min      2.81
_cell_volume                     1363.46(12)
_computing_cell_refinement       'SMART, SAINT'
_computing_data_collection       SMART
_computing_data_reduction        SAINT
_computing_molecular_graphics    'SHELXP-93 (Sheldrick, 1993)'
_computing_publication_material  'SHELXCIF-93 (Sheldrick, 1993)'
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1990)'
_diffrn_ambient_temperature      173(2)
_diffrn_measured_fraction_theta_full 0.948
_diffrn_measured_fraction_theta_max 0.948
_diffrn_measurement_device_type  'Bruker SMART APEX CCD'
_diffrn_measurement_method       '0.3 deg wide \w exposures'
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'fine-focus sealed tube'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0166
_diffrn_reflns_av_sigmaI/netI    0.0158
_diffrn_reflns_limit_h_max       9
_diffrn_reflns_limit_h_min       -9
_diffrn_reflns_limit_k_max       17
_diffrn_reflns_limit_k_min       -17
_diffrn_reflns_limit_l_max       17
_diffrn_reflns_limit_l_min       -18
_diffrn_reflns_number            11679
_diffrn_reflns_theta_full        28.27
_diffrn_reflns_theta_max         28.27
_diffrn_reflns_theta_min         2.12
_diffrn_standards_decay_%        0
_diffrn_standards_interval_count na
_diffrn_standards_interval_time  na
_diffrn_standards_number         'none (area detector data)'
_exptl_absorpt_coefficient_mu    5.558
_exptl_absorpt_correction_T_max  0.7685
_exptl_absorpt_correction_T_min  0.3259
_exptl_absorpt_correction_type   'multi-scan (SADABS)'
_exptl_crystal_colour            colorless
_exptl_crystal_density_diffrn    1.609
_exptl_crystal_density_method    none
_exptl_crystal_description       plate
_exptl_crystal_F_000             656
_exptl_crystal_size_max          0.26
_exptl_crystal_size_mid          0.12
_exptl_crystal_size_min          0.05
_refine_diff_density_max         0.349
_refine_diff_density_min         -0.553
_refine_diff_density_rms         0.091
_refine_ls_extinction_coef       noref
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.065
_refine_ls_hydrogen_treatment    refall
_refine_ls_matrix_type           full
_refine_ls_number_parameters     189
_refine_ls_number_reflns         3218
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.065
_refine_ls_R_factor_all          0.0235
_refine_ls_R_factor_gt           0.0201
_refine_ls_shift/su_max          0.002
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0335P)^2^+0.0919P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0511
_refine_ls_wR_factor_ref         0.0526
_reflns_number_gt                2879
_reflns_number_total             3218
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            ja065037jsi20060721_015540.cif
_cod_data_source_block           Se2Si2C8H20_27a
_cod_database_code               4111083