Half-Chair Conformation of <i>trans</i>-1,4-Dimethyl-7,7-diphenylbicyclo[4.1.0]hepta-2,5-dione
Moriwaki, H.; Kawamoto, T.; Oshima, T.; Acta Crystallographica Section C 52 (1996) 2269–2271; doi:10.1107/S0108270196003435

data_2005412
_publ_section_title
;
 Half-Chair Conformation of
 <i>trans</i>-1,4-Dimethyl-7,7-diphenylbicyclo[4.1.0]hepta-2,5-dione
;
_journal_issue                   9
_journal_name_full               'Acta Crystallographica Section C'
_journal_page_first              2269
_journal_page_last               2271
_journal_paper_doi               10.1107/S0108270196003435
_journal_volume                  52
_journal_year                    1996
_chemical_formula_moiety         'C21 H20 O2'
_chemical_formula_sum            'C21 H20 O2'
_chemical_formula_weight         304.37
_chemical_name_systematic
;
trans-1,4-dimethyl-7,7-diphenylbicyclo[4.1.0]hepta-2,5-dione
;
_space_group_IT_number           14
_symmetry_cell_setting           monoclinic
_symmetry_space_group_name_Hall  '-P 2yab'
_symmetry_space_group_name_H-M   'P 1 21/a 1'
_atom_type_scat_source           IntTabIV
_cell_angle_alpha                90.
_cell_angle_beta                 96.36(3)
_cell_angle_gamma                90.
_cell_formula_units_Z            4
_cell_length_a                   8.925(4)
_cell_length_b                   23.480(12)
_cell_length_c                   8.049(3)
_cell_measurement_reflns_used    22
_cell_measurement_temperature    296
_cell_measurement_theta_max      17.5
_cell_measurement_theta_min      15.9
_cell_volume                     1676.4(13)
_computing_cell_refinement       Crystan-GM
_computing_data_collection       Crystan-GM
_computing_data_reduction        Crystan-GM
_computing_molecular_graphics    Crystan-GM
_computing_publication_material  Crystan-GM
_computing_structure_refinement  Crystan-GM
_computing_structure_solution    Crystan-GM
_diffrn_ambient_temperature      296
_diffrn_measurement_device       'Mac Science MXC3'
_diffrn_measurement_method       \q/\w
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         xray_tube
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.045
_diffrn_reflns_limit_h_max       11
_diffrn_reflns_limit_h_min       0
_diffrn_reflns_limit_k_max       0
_diffrn_reflns_limit_k_min       -30
_diffrn_reflns_limit_l_max       10
_diffrn_reflns_limit_l_min       -10
_diffrn_reflns_number            4531
_diffrn_reflns_theta_max         27.5
_diffrn_standards_decay_%        'not significant'
_diffrn_standards_interval_count 100
_diffrn_standards_number         3
_exptl_absorpt_coefficient_mu    0.071
_exptl_absorpt_correction_T_max  0.998
_exptl_absorpt_correction_T_min  0.817
_exptl_absorpt_correction_type   refdelf
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.21
_exptl_crystal_density_meas      1.21
_exptl_crystal_density_method    flotation
_exptl_crystal_description       prism
_exptl_crystal_F_000             648
_exptl_crystal_size_max          0.50
_exptl_crystal_size_mid          0.35
_exptl_crystal_size_min          0.30
_refine_diff_density_max         0.68
_refine_diff_density_min         -0.42
_refine_ls_extinction_coef       0.0000
_refine_ls_extinction_method     'Larson (1970)'
_refine_ls_goodness_of_fit_obs   0.81
_refine_ls_hydrogen_treatment    refU
_refine_ls_matrix_type           full
_refine_ls_number_parameters     228
_refine_ls_number_reflns         2597
_refine_ls_R_factor_obs          0.0699
_refine_ls_shift/esd_max         0.0180
_refine_ls_structure_factor_coef F
_refine_ls_weighting_scheme      'Weighting scheme based on counting statistics'
_refine_ls_wR_factor_obs         0.0709
_reflns_number_observed          3340
_reflns_number_total             3840
_reflns_observed_criterion       refl_observed_if_F_>_3_sigma(F)
_cod_data_source_file            oa1000.cif
_cod_data_source_block           I
_cod_original_cell_volume        1676.0(10)
_cod_original_sg_symbol_H-M      'P 21/a'
_cod_database_code               2005412