Structure, conformation, and dynamic processes of the stereolabile atropisomers of hindered terphenyl hydrocarbons.
Lunazzi, Lodovico; Mazzanti, Andrea; Minzoni, Mirko; Anderson, J. Edgar; Organic letters 7 (2005) 1291–1294; doi:10.1021/ol050091a

data_1506514
_publ_contact_author
;
Dr. Andrea Mazzanti
Universita di Bologna
Dipartimento di Chimica Organica A.Mangini
Viale Risorgimento 4
40136 Bologna
Italy
;
_publ_section_title
;
 Structure, conformation, and dynamic processes of the stereolabile
 atropisomers of hindered terphenyl hydrocarbons.
;
_journal_issue                   7
_journal_name_full               'Organic letters'
_journal_page_first              1291
_journal_page_last               1294
_journal_paper_doi               10.1021/ol050091a
_journal_volume                  7
_journal_year                    2005
_chemical_formula_moiety         'C20 H18'
_chemical_formula_sum            'C20 H18'
_chemical_formula_weight         258.34
_chemical_melting_point          146
_chemical_name_systematic
; 
 1,4-Bis-(2-methyl-phenyl)-benzene 
;
_space_group_IT_number           61
_symmetry_cell_setting           orthorhombic
_symmetry_space_group_name_Hall  '-P 2ac 2ab'
_symmetry_space_group_name_H-M   'P b c a'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_audit_creation_date             16/11/2004
_audit_creation_method           SHELXL-97
_cell_angle_alpha                90.00
_cell_angle_beta                 90.00
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   10.7905(12)
_cell_length_b                   7.6750(8)
_cell_length_c                   17.5436(19)
_cell_measurement_temperature    273(2)
_cell_volume                     1452.9(3)
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1990)'
_diffrn_ambient_temperature      273(2)
_diffrn_measured_fraction_theta_full 0.987
_diffrn_measured_fraction_theta_max 0.987
_diffrn_measurement_device_type  'Bruker APEX'
_diffrn_measurement_method       'omega scan'
_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  0.0239
_diffrn_reflns_av_sigmaI/netI    0.0143
_diffrn_reflns_limit_h_max       14
_diffrn_reflns_limit_h_min       -14
_diffrn_reflns_limit_k_max       10
_diffrn_reflns_limit_k_min       -10
_diffrn_reflns_limit_l_max       23
_diffrn_reflns_limit_l_min       -23
_diffrn_reflns_number            14603
_diffrn_reflns_theta_full        28.21
_diffrn_reflns_theta_max         28.21
_diffrn_reflns_theta_min         2.99
_exptl_absorpt_coefficient_mu    0.066
_exptl_absorpt_correction_T_max  0.9868
_exptl_absorpt_correction_T_min  0.9739
_exptl_absorpt_correction_type   empirical
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.181
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       blocks
_exptl_crystal_F_000             552
_exptl_crystal_size_max          0.40
_exptl_crystal_size_mid          0.40
_exptl_crystal_size_min          0.20
_refine_diff_density_max         0.135
_refine_diff_density_min         -0.151
_refine_diff_density_rms         0.028
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.073
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     92
_refine_ls_number_reflns         1765
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.073
_refine_ls_R_factor_all          0.0492
_refine_ls_R_factor_gt           0.0369
_refine_ls_shift/su_max          0.000
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0503P)^2^+0.1543P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0976
_refine_ls_wR_factor_ref         0.1038
_reflns_number_gt                1353
_reflns_number_total             1765
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            ol050091asi20050117_061247.cif
_cod_data_source_block           trisme
_cod_database_code               1506514