Intramolecular and Intermolecular Contributions to the Barriers for Rotation of Methyl Groups in Crystalline Solids: Electronic Structure Calculations and Solid-State NMR Relaxation Measurements
Xianlong Wang; Peter A. Beckmann; Clelia W. Mallory; Arnold L. Rheingold; Antonio G. DiPasquale; Patrick J. Carroll; Frank B. Mallory; Journal of Organic Chemistry 76 (2011) 5170–5176; doi:10.1021/jo2006818

data_4026424
_publ_section_title
;
 Intramolecular and Intermolecular Contributions to the Barriers for
 Rotation of Methyl Groups in Crystalline Solids: Electronic Structure
 Calculations and Solid-State NMR Relaxation Measurements
;
_journal_name_full               'Journal of Organic Chemistry'
_journal_page_first              5170
_journal_page_last               5176
_journal_paper_doi               10.1021/jo2006818
_journal_volume                  76
_journal_year                    2011
_chemical_formula_sum            'C16 H14'
_chemical_formula_weight         206.27
_chemical_name_common            3,9-dimethylphenanthrene
_space_group_IT_number           14
_symmetry_cell_setting           monoclinic
_symmetry_space_group_name_Hall  '-P 2yn'
_symmetry_space_group_name_H-M   'P 1 21/n 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                 105.136(2)
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   13.5583(12)
_cell_length_b                   4.8269(4)
_cell_length_c                   17.3642(15)
_cell_measurement_reflns_used    1868
_cell_measurement_temperature    100(2)
_cell_measurement_theta_max      27.45
_cell_measurement_theta_min      2.21
_cell_volume                     1096.97(16)
_computing_cell_refinement       'Bruker SMART'
_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 0.968
_diffrn_measured_fraction_theta_max 0.968
_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  0.0183
_diffrn_reflns_av_sigmaI/netI    0.0267
_diffrn_reflns_limit_h_max       17
_diffrn_reflns_limit_h_min       -16
_diffrn_reflns_limit_k_max       5
_diffrn_reflns_limit_k_min       -6
_diffrn_reflns_limit_l_max       22
_diffrn_reflns_limit_l_min       -22
_diffrn_reflns_number            6327
_diffrn_reflns_theta_full        27.47
_diffrn_reflns_theta_max         27.47
_diffrn_reflns_theta_min         1.71
_exptl_absorpt_coefficient_mu    0.070
_exptl_absorpt_correction_T_max  0.919
_exptl_absorpt_correction_T_min  0.877
_exptl_absorpt_correction_type   none
_exptl_absorpt_process_details   sadabs
_exptl_crystal_colour            colorless
_exptl_crystal_density_diffrn    1.249
_exptl_crystal_description       blade
_exptl_crystal_F_000             440
_exptl_crystal_size_max          0.15
_exptl_crystal_size_mid          0.10
_exptl_crystal_size_min          0.04
_refine_diff_density_max         0.269
_refine_diff_density_min         -0.237
_refine_diff_density_rms         0.050
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.055
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     147
_refine_ls_number_reflns         2446
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.055
_refine_ls_R_factor_all          0.0773
_refine_ls_R_factor_gt           0.0541
_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^)+(0.0708P)^2^+0.6378P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1428
_refine_ls_wR_factor_ref         0.1550
_reflns_number_gt                1759
_reflns_number_total             2446
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            jo2006818_si_002.cif
_cod_data_source_block           beck12
_cod_database_code               4026424