Rotational Energy Barrier of 2-(2',6'-Dihydroxyphenyl)benzoxazole: A Case Study by NMR
Weihua Chen; Eric B. Twum; Linlin Li; Brian D. Wright; Peter L. Rinaldi; Yi Pang; Journal of Organic Chemistry 77 (2012) 285–290; doi:10.1021/jo201890f

data_4026840
_publ_section_title
;
 Rotational Energy Barrier of 2-(2',6'-Dihydroxyphenyl)benzoxazole: A Case
 Study by NMR
;
_journal_name_full               'Journal of Organic Chemistry'
_journal_page_first              285
_journal_page_last               290
_journal_paper_doi               10.1021/jo201890f
_journal_volume                  77
_journal_year                    2012
_chemical_formula_moiety         'C13 H9 N O3'
_chemical_formula_sum            'C13 H9 N O3'
_chemical_formula_weight         227.21
_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                 101.652(9)
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   16.301(10)
_cell_length_b                   4.863(3)
_cell_length_c                   13.818(8)
_cell_measurement_reflns_used    1951
_cell_measurement_temperature    100(2)
_cell_measurement_theta_max      26.25
_cell_measurement_theta_min      2.55
_cell_volume                     1072.8(11)
_computing_cell_refinement       'Bruker SAINT'
_computing_data_collection       'Bruker SMART'
_computing_data_reduction        'Bruker SAINT'
_computing_molecular_graphics    'Bruker SHELXTL'
_computing_publication_material  'Bruker SHELXTL'
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1990)'
_diffrn_ambient_temperature      100(2)
_diffrn_measured_fraction_theta_full 0.972
_diffrn_measured_fraction_theta_max 0.972
_diffrn_measurement_device_type  'CCD area detector'
_diffrn_measurement_method       'phi and omega scans'
_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  0.0979
_diffrn_reflns_av_sigmaI/netI    0.0894
_diffrn_reflns_limit_h_max       20
_diffrn_reflns_limit_h_min       -20
_diffrn_reflns_limit_k_max       5
_diffrn_reflns_limit_k_min       -5
_diffrn_reflns_limit_l_max       17
_diffrn_reflns_limit_l_min       -16
_diffrn_reflns_number            6934
_diffrn_reflns_theta_full        26.28
_diffrn_reflns_theta_max         26.28
_diffrn_reflns_theta_min         2.55
_exptl_absorpt_coefficient_mu    0.102
_exptl_absorpt_correction_T_max  0.9960
_exptl_absorpt_correction_T_min  0.1907
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   SADABS
_exptl_crystal_colour            colorless
_exptl_crystal_density_diffrn    1.407
_exptl_crystal_description       Rod
_exptl_crystal_F_000             472
_exptl_crystal_size_max          0.89
_exptl_crystal_size_mid          0.09
_exptl_crystal_size_min          0.04
_refine_diff_density_max         0.269
_refine_diff_density_min         -0.298
_refine_diff_density_rms         0.069
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   0.890
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     156
_refine_ls_number_reflns         2099
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      0.890
_refine_ls_R_factor_all          0.1100
_refine_ls_R_factor_gt           0.0679
_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^)+(0.1075P)^2^+0.0000P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1644
_refine_ls_wR_factor_ref         0.1784
_reflns_number_gt                1214
_reflns_number_total             2099
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            jo201890f_si_002.cif
_cod_data_source_block           bw
_cod_original_cell_volume        1072.7(11)
_cod_original_sg_symbol_H-M      'P 1 21/c 1 '
_cod_database_code               4026840