Stereospecific Ring Contraction of Bromocycloheptenes through Dyotropic Rearrangements via Nonclassical Carbocation-Anion Pairs.
Goh, Shermin S.; Champagne, Pier Alexandre; Guduguntla, Sureshbabu; Kikuchi, Takashi; Fujita, Makoto; Houk, K. N.; Feringa, Ben L.; Journal of the American Chemical Society 140 (2018) 4986–4990; doi:10.1021/jacs.8b00821

data_4132042
_publ_section_title
;
 Stereospecific Ring Contraction of Bromocycloheptenes through Dyotropic
 Rearrangements via Nonclassical Carbocation-Anion Pairs.
;
_journal_issue                   15
_journal_name_full               'Journal of the American Chemical Society'
_journal_page_first              4986
_journal_page_last               4990
_journal_paper_doi               10.1021/jacs.8b00821
_journal_volume                  140
_journal_year                    2018
_chemical_absolute_configuration R,R
_chemical_formula_moiety
'(C72 H48 N24 I12 Zn6), 4.81(C11 H19 Br), 0.59(C6 H12)'
_chemical_formula_sum            'C128.45 H146.48 Br4.81 I12 N24 Zn6'
_chemical_formula_weight         4325.55
_space_group_crystal_system      monoclinic
_space_group_IT_number           5
_space_group_name_Hall           'C 2y'
_space_group_name_H-M_alt        'C 1 2 1'
_atom_sites_solution_hydrogens   geom
_audit_creation_method           SHELXL-2014/7
_cell_angle_alpha                90
_cell_angle_beta                 101.3300(10)
_cell_angle_gamma                90
_cell_formula_units_Z            4
_cell_length_a                   35.1167(5)
_cell_length_b                   14.8989(2)
_cell_length_c                   30.9479(4)
_cell_measurement_reflns_used    38132
_cell_measurement_temperature    93(2)
_cell_measurement_theta_max      28.8160
_cell_measurement_theta_min      2.4910
_cell_volume                     15876.4(4)
_computing_cell_refinement       'CrysAlisPro 1.171.38.41 (Rigaku OD, 2015)'
_computing_data_collection       'CrysAlisPro 1.171.38.41 (Rigaku OD, 2015)'
_computing_data_reduction        'CrysAlisPro 1.171.38.41 (Rigaku OD, 2015)'
_computing_molecular_graphics    'shelXle (Hubschle et al., 2011)'
_computing_publication_material  'SHELXL-2014/7 (Sheldrick, 2014)'
_computing_structure_refinement  'SHELXL-2014/7 (Sheldrick, 2014)'
_computing_structure_solution    'SHELXT-2014/5 (Sheldrick, 2014)'
_diffrn_ambient_temperature      93(2)
_diffrn_detector_area_resol_mean 5.811
_diffrn_measured_fraction_theta_full 0.999
_diffrn_measured_fraction_theta_max 0.926
_diffrn_measurement_device_type
'dtrek-CrysAlisPro-abstract goniometer imported rigaku-d*trek images'
_diffrn_measurement_method       '\w scans'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71075
_diffrn_reflns_av_R_equivalents  0.0191
_diffrn_reflns_av_unetI/netI     0.0276
_diffrn_reflns_Laue_measured_fraction_full 0.999
_diffrn_reflns_Laue_measured_fraction_max 0.926
_diffrn_reflns_limit_h_max       47
_diffrn_reflns_limit_h_min       -47
_diffrn_reflns_limit_k_max       20
_diffrn_reflns_limit_k_min       -20
_diffrn_reflns_limit_l_max       41
_diffrn_reflns_limit_l_min       -41
_diffrn_reflns_number            85365
_diffrn_reflns_point_group_measured_fraction_full 0.977
_diffrn_reflns_point_group_measured_fraction_max 0.870
_diffrn_reflns_theta_full        25.242
_diffrn_reflns_theta_max         28.979
_diffrn_reflns_theta_min         2.329
_diffrn_source                   'fine-focus sealed X-ray tube'
_exptl_absorpt_coefficient_mu    4.485
_exptl_absorpt_correction_T_max  1.00000
_exptl_absorpt_correction_T_min  0.41880
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details
;
CrysAlisPro 1.171.38.41 (Rigaku Oxford Diffraction, 2015)
Empirical absorption correction using spherical harmonics,
 implemented in SCALE3 ABSPACK scaling algorithm.
;
_exptl_crystal_colour            colorless
_exptl_crystal_density_diffrn    1.810
_exptl_crystal_description       block
_exptl_crystal_F_000             8277
_exptl_crystal_size_max          0.320
_exptl_crystal_size_mid          0.160
_exptl_crystal_size_min          0.070
_refine_diff_density_max         1.746
_refine_diff_density_min         -2.915
_refine_diff_density_rms         0.148
_refine_ls_abs_structure_details
;
 Flack x determined using 13083 quotients [(I+)-(I-)]/[(I+)+(I-)]
 (Parsons, Flack and Wagner, Acta Cryst. B69 (2013) 249-259).
;
_refine_ls_abs_structure_Flack   0.031(16)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.061
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     2068
_refine_ls_number_reflns         36663
_refine_ls_number_restraints     1497
_refine_ls_restrained_S_all      1.060
_refine_ls_R_factor_all          0.0638
_refine_ls_R_factor_gt           0.0565
_refine_ls_shift/su_max          0.001
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'w=1/[\s^2^(Fo^2^)+(0.1105P)^2^+54.1624P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1567
_refine_ls_wR_factor_ref         0.1625
_reflns_Friedel_coverage         0.813
_reflns_Friedel_fraction_full    0.953
_reflns_Friedel_fraction_max     0.810
_reflns_number_gt                31966
_reflns_number_total             36663
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            ja8b00821_si_003.cif
_cod_data_source_block           SHELXT_b
_cod_original_sg_symbol_H-M      'C 2'
_cod_database_code               4132042
_shelx_shelxl_version_number     2014/7
_shelx_res_checksum              9999
_shelx_hkl_checksum              81451