Experimental Verification of the Homoaromaticity of 1,3,5-Cycloheptatriene and Evaluation of the Aromaticity of Tropone and the Tropylium Cation by Use of the Dimethyldihydropyrene Probe
Richard Vaughan Williams; W. Daniel Edwards; Pengrong Zhang; David J. Berg; Reginald H. Mitchell; Journal of the American Chemical Society 134 (2012) 16742–16752; doi:10.1021/ja306868r

data_4118732
_publ_section_title
;
 Experimental Verification of the Homoaromaticity of
 1,3,5-Cycloheptatriene and Evaluation of the Aromaticity of Tropone and
 the Tropylium Cation by Use of the Dimethyldihydropyrene Probe
;
_journal_name_full               'Journal of the American Chemical Society'
_journal_page_first              16742
_journal_page_last               16752
_journal_paper_doi               10.1021/ja306868r
_journal_volume                  134
_journal_year                    2012
_chemical_formula_sum            'C33 H40'
_chemical_formula_weight         436.65
_chemical_name_systematic
;
 ?
;
_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   geom
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_audit_creation_method           SHELXL-97
_cell_angle_alpha                90.00
_cell_angle_beta                 110.7400(10)
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   15.2931(5)
_cell_length_b                   15.5885(4)
_cell_length_c                   11.6512(3)
_cell_measurement_reflns_used    4523
_cell_measurement_temperature    173(2)
_cell_measurement_theta_max      27.30
_cell_measurement_theta_min      2.85
_cell_volume                     2597.61(13)
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_diffrn_ambient_temperature      173(2)
_diffrn_measured_fraction_theta_full 0.981
_diffrn_measured_fraction_theta_max 0.981
_diffrn_measurement_device_type  'Bruker X8 APEX II'
_diffrn_measurement_method       'area detector'
_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  0.0489
_diffrn_reflns_av_sigmaI/netI    0.0546
_diffrn_reflns_limit_h_max       20
_diffrn_reflns_limit_h_min       -19
_diffrn_reflns_limit_k_max       20
_diffrn_reflns_limit_k_min       -19
_diffrn_reflns_limit_l_max       15
_diffrn_reflns_limit_l_min       -11
_diffrn_reflns_number            23726
_diffrn_reflns_theta_full        28.02
_diffrn_reflns_theta_max         28.02
_diffrn_reflns_theta_min         2.28
_exptl_absorpt_coefficient_mu    0.062
_exptl_absorpt_correction_T_max  0.979
_exptl_absorpt_correction_T_min  0.835
_exptl_absorpt_correction_type   multi-scan
_exptl_crystal_colour            needle
_exptl_crystal_density_diffrn    1.117
_exptl_crystal_description       red
_exptl_crystal_F_000             952
_exptl_crystal_size_max          0.45
_exptl_crystal_size_mid          0.40
_exptl_crystal_size_min          0.36
_refine_diff_density_max         0.351
_refine_diff_density_min         -0.232
_refine_diff_density_rms         0.048
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.024
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     337
_refine_ls_number_reflns         6164
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.024
_refine_ls_R_factor_all          0.1123
_refine_ls_R_factor_gt           0.0512
_refine_ls_shift/su_max          0.001
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0800P)^2^+0.1315P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1286
_refine_ls_wR_factor_ref         0.1599
_reflns_number_gt                3536
_reflns_number_total             6164
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            ja306868r_si_004.cif
_cod_data_source_block           p21c
_cod_original_sg_symbol_H-M      'P 21/c'
_cod_database_code               4118732