Temporary and Permanent Trapping of the Metastable Twisted Conformer of an Overcrowded Chromic Alkene via Encapsulation
Hiroki Takezawa; Takashi Murase; Makoto Fujita; Journal of the American Chemical Society 134 (2012) 17420–17423; doi:10.1021/ja308101a

data_4118811
_publ_contact_author             'Makoto Fujita'
_publ_contact_author_email       mfujita@appchem.t.u-tokyo.ac.jp
_publ_section_title
;
 Temporary and Permanent Trapping of the Metastable Twisted Conformer of
 an Overcrowded Chromic Alkene via Encapsulation
;
_journal_name_full               'Journal of the American Chemical Society'
_journal_page_first              17420
_journal_page_last               17423
_journal_paper_doi               10.1021/ja308101a
_journal_volume                  134
_journal_year                    2012
_chemical_formula_sum            'C30 H16 Br4 Cl4 O3'
_chemical_formula_weight         885.87
_chemical_name_systematic
; 
 ? 
;
_space_group_IT_number           61
_symmetry_cell_setting           orthorhombic
_symmetry_space_group_name_Hall  '-P 2ac 2ab'
_symmetry_space_group_name_H-M   'P b c a'
_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            8
_cell_length_a                   20.709(3)
_cell_length_b                   12.9232(18)
_cell_length_c                   23.009(3)
_cell_measurement_reflns_used    7436
_cell_measurement_temperature    90(2)
_cell_measurement_theta_max      26.638
_cell_measurement_theta_min      2.502
_cell_volume                     6157.8(15)
_computing_cell_refinement       'Bruker SAINT'
_computing_data_collection       'Bruker APEX-II'
_computing_data_reduction        'Bruker SAINT'
_computing_molecular_graphics    'Bruker XP'
_computing_publication_material  'Bruker SHELXTL'
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1990)'
_diffrn_ambient_temperature      90(2)
_diffrn_measured_fraction_theta_full 0.950
_diffrn_measured_fraction_theta_max 0.950
_diffrn_measurement_device_type  'CCD area detector'
_diffrn_measurement_method       'omega scan'
_diffrn_radiation_monochromator  'focusing mirror'
_diffrn_radiation_source         'fine-focus rotating anode'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0631
_diffrn_reflns_av_sigmaI/netI    0.0292
_diffrn_reflns_limit_h_max       26
_diffrn_reflns_limit_h_min       -26
_diffrn_reflns_limit_k_max       17
_diffrn_reflns_limit_k_min       -17
_diffrn_reflns_limit_l_max       29
_diffrn_reflns_limit_l_min       -29
_diffrn_reflns_number            116333
_diffrn_reflns_theta_full        28.53
_diffrn_reflns_theta_max         28.53
_diffrn_reflns_theta_min         1.77
_diffrn_standards_decay_%        none
_exptl_absorpt_coefficient_mu    5.608
_exptl_absorpt_correction_T_max  0.9206
_exptl_absorpt_correction_T_min  0.6472
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   SADABS
_exptl_crystal_colour            blue
_exptl_crystal_density_diffrn    1.911
_exptl_crystal_description       Plate
_exptl_crystal_F_000             3424
_exptl_crystal_size_max          0.09
_exptl_crystal_size_mid          0.04
_exptl_crystal_size_min          0.02
_refine_diff_density_max         1.881
_refine_diff_density_min         -1.556
_refine_diff_density_rms         0.137
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.074
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     434
_refine_ls_number_reflns         7436
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.074
_refine_ls_R_factor_all          0.0672
_refine_ls_R_factor_gt           0.0405
_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^)+(0.0126P)^2^+39.2771P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0721
_refine_ls_wR_factor_ref         0.0838
_reflns_number_gt                5722
_reflns_number_total             7436
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            ja308101a_si_002.cif
_cod_data_source_block           br4
_cod_database_code               4118811