Butane-1,4-diyl dications stabilized by steric factors: electrochiroptical response systems based on reversible interconversion between dihydro[5]helicene-type electron acceptors and electron-donating 1,1'-binaphthyls.
Ohta, Eisuke; Higuchi, Hiroki; Kawai, Hidetoshi; Fujiwara, Kenshu; Suzuki, Takanori; Organic & biomolecular chemistry 3 (2005) 3024–3031; doi:10.1039/b506435j

data_7150217
_publ_section_title
;
 Butane-1,4-diyl dications stabilized by steric factors:
 electrochiroptical response systems based on reversible
 interconversion between dihydro[5]helicene-type electron acceptors and
 electron-donating 1,1'-binaphthyls.
;
_journal_issue                   16
_journal_name_full               'Organic &amp; biomolecular chemistry'
_journal_page_first              3024
_journal_page_last               3031
_journal_paper_doi               10.1039/b506435j
_journal_volume                  3
_journal_year                    2005
_chemical_formula_moiety         'C48 H30 O2 '
_chemical_formula_sum            'C48 H30 O2'
_chemical_formula_weight         638.76
_space_group_IT_number           14
_symmetry_cell_setting           monoclinic
_symmetry_Int_Tables_number      14
_symmetry_space_group_name_Hall  '-P 2yn'
_symmetry_space_group_name_H-M   'P 1 21/n 1'
_cell_angle_alpha                90.000(2)
_cell_angle_beta                 110.328(2)
_cell_angle_gamma                90.000(2)
_cell_formula_units_Z            4
_cell_length_a                   11.977(3)
_cell_length_b                   24.465(6)
_cell_length_c                   12.250(4)
_cell_measurement_reflns_used    5631
_cell_measurement_temperature    293.1
_cell_measurement_theta_max      27.5
_cell_measurement_theta_min      3.1
_cell_volume                     3365.9(16)
_computing_cell_refinement       CRYSTALCLEAR
_computing_data_collection       CRYSTALCLEAR
_computing_data_reduction        'teXsan Ver. 1.11'
_computing_publication_material  'teXsan Ver. 1.11'
_computing_structure_refinement  'teXsan Ver. 1.10'
_computing_structure_solution    SIR92
_diffrn_detector_area_resol_mean 14.71
_diffrn_measured_fraction_theta_full 3.2594
_diffrn_measured_fraction_theta_max 3.2594
_diffrn_measurement_device_type  'Rigaku/MSC Mercury CCD'
_diffrn_measurement_method       \w
_diffrn_radiation_type           'Mo K\a'
_diffrn_radiation_wavelength     0.7107
_diffrn_reflns_av_R_equivalents  0.060
_diffrn_reflns_limit_h_max       15
_diffrn_reflns_limit_h_min       -14
_diffrn_reflns_limit_k_max       30
_diffrn_reflns_limit_k_min       -30
_diffrn_reflns_limit_l_max       10
_diffrn_reflns_limit_l_min       -15
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_diffrn_reflns_theta_full        27.48
_diffrn_reflns_theta_max         27.48
_exptl_absorpt_coefficient_mu    0.075
_exptl_absorpt_correction_T_max  0.998
_exptl_absorpt_correction_T_min  0.998
_exptl_absorpt_correction_type   none
_exptl_crystal_colour            Yellow
_exptl_crystal_density_diffrn    1.260
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       Block
_exptl_crystal_size_max          0.100
_exptl_crystal_size_mid          0.030
_exptl_crystal_size_min          0.030
_refine_diff_density_max         0.42
_refine_diff_density_min         -0.41
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   0.888
_refine_ls_hydrogen_treatment    noref
_refine_ls_number_parameters     451
_refine_ls_number_reflns         7457
_refine_ls_R_factor_gt           0.0620
_refine_ls_shift/su_max          0.0085
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'w = 1/[\s^2^(Fo^2^) + (0.05000(Max(Fo^2^,0) + 2Fc^2^)/3)^2^]'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_ref         0.1640
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_reflns_threshold_expression     F^2^>2.0\s(F^2^)
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_cod_data_source_block           '_040121r'
_cod_original_cell_volume        3365.8(1)
_cod_original_formula_sum        'C48 H30 O2 '
_cod_database_code               7150217