Rotation of Aryl Groups in 9,10-Diarylphenanthrenes: Does the Rotational Barrier Become Lower as the Backbone Becomes More Crowded?
Li, Jen-Yi; Chang, Hung-Ing; Feng, Chieh-Ning; Wu, Yao-Ting; Organic letters 18 (2016) 6444–6447; doi:10.1021/acs.orglett.6b03343

data_1555977
_publ_section_title
;
 Rotation of Aryl Groups in 9,10-Diarylphenanthrenes: Does the Rotational
 Barrier Become Lower as the Backbone Becomes More Crowded?
;
_journal_issue                   24
_journal_name_full               'Organic letters'
_journal_page_first              6444
_journal_page_last               6447
_journal_paper_doi               10.1021/acs.orglett.6b03343
_journal_volume                  18
_journal_year                    2016
_chemical_absolute_configuration rm
_chemical_formula_sum            'C34 H34'
_chemical_formula_weight         442.61
_space_group_crystal_system      orthorhombic
_space_group_IT_number           19
_space_group_name_Hall           'P 2ac 2ab'
_space_group_name_H-M_alt        'P 21 21 21'
_atom_sites_solution_hydrogens   geom
_audit_creation_method           SHELXL-2014/6
_cell_angle_alpha                90
_cell_angle_beta                 90
_cell_angle_gamma                90
_cell_formula_units_Z            4
_cell_length_a                   7.2192(9)
_cell_length_b                   12.2678(16)
_cell_length_c                   27.633(3)
_cell_measurement_reflns_used    4875
_cell_measurement_temperature    100(2)
_cell_measurement_theta_max      24.2965
_cell_measurement_theta_min      2.2201
_cell_volume                     2447.3(5)
_computing_cell_refinement       'SAINT V8.34A (Bruker AXS Inc., 2013)'
_computing_data_collection       'APEX2 (Bruker AXS, 2010)'
_computing_data_reduction        'SAINT V8.34A (Bruker AXS Inc., 2013)'
_computing_molecular_graphics    'SHELXTL (Sheldrick, 2008)'
_computing_publication_material  SHELXTL
_computing_structure_refinement  'SHELXL-2014/6 (Sheldrick, 2014)'
_diffrn_ambient_temperature      100(2)
_diffrn_detector_area_resol_mean 8.3333
_diffrn_measured_fraction_theta_full 1.000
_diffrn_measured_fraction_theta_max 0.996
_diffrn_measurement_device_type  'Bruker APEX-II CCD'
_diffrn_measurement_method       '\f and \w scans'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0763
_diffrn_reflns_av_unetI/netI     0.0795
_diffrn_reflns_Laue_measured_fraction_full 1.000
_diffrn_reflns_Laue_measured_fraction_max 0.996
_diffrn_reflns_limit_h_max       8
_diffrn_reflns_limit_h_min       -9
_diffrn_reflns_limit_k_max       15
_diffrn_reflns_limit_k_min       -15
_diffrn_reflns_limit_l_max       24
_diffrn_reflns_limit_l_min       -34
_diffrn_reflns_number            19855
_diffrn_reflns_point_group_measured_fraction_full 1.000
_diffrn_reflns_point_group_measured_fraction_max 0.996
_diffrn_reflns_theta_full        25.242
_diffrn_reflns_theta_max         26.475
_diffrn_reflns_theta_min         1.474
_exptl_absorpt_coefficient_mu    0.067
_exptl_absorpt_correction_T_max  0.9334
_exptl_absorpt_correction_T_min  0.8365
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   'SADABS V2014/4 (Bruker AXS Inc.)'
_exptl_crystal_colour            Colorless
_exptl_crystal_density_diffrn    1.201
_exptl_crystal_density_meas      ?
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       Lump
_exptl_crystal_F_000             952
_exptl_crystal_size_max          0.20
_exptl_crystal_size_mid          0.12
_exptl_crystal_size_min          0.12
_refine_diff_density_max         0.880
_refine_diff_density_min         -0.338
_refine_diff_density_rms         0.063
_refine_ls_abs_structure_details
;
 Refined as an inversion twin.
;
_refine_ls_abs_structure_Flack   -2(10)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.052
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     316
_refine_ls_number_reflns         5022
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.052
_refine_ls_R_factor_all          0.0808
_refine_ls_R_factor_gt           0.0683
_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^)+(0.1041P)^2^+0.4892P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1853
_refine_ls_wR_factor_ref         0.1947
_reflns_Friedel_coverage         0.743
_reflns_Friedel_fraction_full    1.000
_reflns_Friedel_fraction_max     0.996
_reflns_number_gt                4032
_reflns_number_total             5022
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            ol6b03343_si_002.cif
_cod_data_source_block           150919lt_0m_a
_cod_depositor_comments
;
The following automatic conversions were performed:

data item '_exptl_crystal_density_meas' value 'not measured' was
changed to '?' -- the value is perceived as not measured.

Automatic conversion script
Id: cif_fix_values 6909 2019-04-08 15:41:33Z antanas 
;
_cod_database_code               1555977
_shelxl_version_number           2014/6
_shelx_res_checksum              74953
_shelx_hkl_checksum              10003