The effect of a highly twisted CC double bond on the electronic structures of 9,9′-bifluorenylidene derivatives in the ground and excited states
Takai, Atsuro; Freas, Dylan J.; Suzuki, Toshikane; Sugimoto, Manabu; Labuta, Jan; Haruki, Rie; Kumai, Reiji; Adachi, Shin-ichi; Sakai, Hayato; Hasobe, Taku; Matsushita, Yoshitaka; Takeuchi, Masayuki; Organic Chemistry Frontiers 4 (2017) 650–; doi:10.1039/C7QO00125H

data_1553747
_publ_section_title
;
 The effect of a highly twisted C&#xE001;C double bond on the electronic
 structures of 9,9&#x2032;-bifluorenylidene derivatives in the ground and
 excited states
;
_journal_issue                   5
_journal_name_full               'Organic Chemistry Frontiers'
_journal_page_first              650
_journal_paper_doi               10.1039/C7QO00125H
_journal_volume                  4
_journal_year                    2017
_chemical_formula_sum            'C30 H24'
_chemical_formula_weight         384.49
_chemical_name_systematic        1,4,1',4?-tetramethyl-9,9?-bifluorenylidene
_space_group_crystal_system      monoclinic
_space_group_IT_number           9
_space_group_name_Hall           'C -2yc'
_space_group_name_H-M_alt        'C 1 c 1'
_atom_sites_solution_hydrogens   geom
_audit_creation_method           SHELXL-2014/7
_audit_update_record
;
2017-02-08 deposited with the CCDC.
2017-03-10 downloaded from the CCDC.
;
_cell_angle_alpha                90
_cell_angle_beta                 122.509(3)
_cell_angle_gamma                90
_cell_formula_units_Z            16
_cell_length_a                   21.7066(8)
_cell_length_b                   21.7067(8)
_cell_length_c                   20.1949(13)
_cell_measurement_reflns_used    2808
_cell_measurement_temperature    213(2)
_cell_measurement_theta_max      23.14
_cell_measurement_theta_min      2.39
_cell_volume                     8024.4(7)
_computing_cell_refinement       'CrystalClear (Rigaku, 1997--2002)'
_computing_data_collection       'CrystalClear (Rigaku, 1997--2002)'
_computing_data_reduction        'CrystalClear (Rigaku, 1997--2002)'
_computing_structure_refinement  'SHELXL-2014/7 (Sheldrick, 2014)'
_computing_structure_solution    'SHELXS-2013 (Sheldrick, 2013)'
_diffrn_ambient_temperature      213(2)
_diffrn_detector_area_resol_mean 28.5714
_diffrn_measured_fraction_theta_full 0.981
_diffrn_measured_fraction_theta_max 0.981
_diffrn_measurement_device
;
Rigaku AFC11 Saturn724+ (4x4 bin mode)
;
_diffrn_measurement_method       dtprofit.ref
_diffrn_radiation_detector       CCD
_diffrn_radiation_monochromator  Confocal
_diffrn_radiation_source         'Rotating Anode'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0804
_diffrn_reflns_av_unetI/netI     0.2141
_diffrn_reflns_Laue_measured_fraction_full 0.981
_diffrn_reflns_Laue_measured_fraction_max 0.981
_diffrn_reflns_limit_h_max       23
_diffrn_reflns_limit_h_min       -25
_diffrn_reflns_limit_k_max       21
_diffrn_reflns_limit_k_min       -25
_diffrn_reflns_limit_l_max       23
_diffrn_reflns_limit_l_min       -23
_diffrn_reflns_number            25013
_diffrn_reflns_point_group_measured_fraction_full 0.981
_diffrn_reflns_point_group_measured_fraction_max 0.981
_diffrn_reflns_theta_full        24.620
_diffrn_reflns_theta_max         24.620
_diffrn_reflns_theta_min         1.876
_exptl_absorpt_coefficient_mu    0.072
_exptl_absorpt_correction_T_max  0.3129
_exptl_absorpt_correction_T_min  0.2602
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details
;
CrystalClear (Rigaku, 1997--2002)
;
_exptl_crystal_colour            'Dark red'
_exptl_crystal_density_diffrn    1.273
_exptl_crystal_description       Chunk
_exptl_crystal_F_000             3264
_exptl_crystal_recrystallization_method 'Vapour deposition'
_exptl_crystal_size_max          0.059
_exptl_crystal_size_mid          0.047
_exptl_crystal_size_min          0.017
_refine_diff_density_max         0.430
_refine_diff_density_min         -0.257
_refine_diff_density_rms         0.068
_refine_ls_abs_structure_details
;
 Refined as an inversion twin.
;
_refine_ls_abs_structure_Flack   10(10)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   0.874
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     1098
_refine_ls_number_reflns         12072
_refine_ls_number_restraints     2
_refine_ls_restrained_S_all      0.874
_refine_ls_R_factor_all          0.1838
_refine_ls_R_factor_gt           0.0776
_refine_ls_shift/su_max          0.000
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details     'w=1/[\s^2^(Fo^2^)] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1578
_refine_ls_wR_factor_ref         0.2027
_reflns_Friedel_coverage         0.998
_reflns_Friedel_fraction_full    0.981
_reflns_Friedel_fraction_max     0.981
_reflns_number_gt                5210
_reflns_number_total             12072
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            c7qo00125h2.cif
_cod_data_source_block           shelx
_cod_original_sg_symbol_H-M      'C c'
_cod_database_code               1553747
_shelx_shelxl_version_number     2014/7
_shelx_estimated_absorpt_t_min   0.996
_shelx_estimated_absorpt_t_max   0.999
_shelx_res_checksum              71743