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_4026426
_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_systematic        1,9-dimethylphenanthrene
_space_group_IT_number           33
_symmetry_cell_setting           orthorhombic
_symmetry_space_group_name_Hall  'P 2c -2n'
_symmetry_space_group_name_H-M   'P n a 21'
_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                 90.00
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   9.301(4)
_cell_length_b                   18.549(9)
_cell_length_c                   6.560(3)
_cell_measurement_reflns_used    2281
_cell_measurement_temperature    213(2)
_cell_measurement_theta_max      28.00
_cell_measurement_theta_min      2.45
_cell_volume                     1131.8(9)
_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      213(2)
_diffrn_measured_fraction_theta_full 0.958
_diffrn_measured_fraction_theta_max 0.958
_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  0.0247
_diffrn_reflns_av_sigmaI/netI    0.0328
_diffrn_reflns_limit_h_max       11
_diffrn_reflns_limit_h_min       -11
_diffrn_reflns_limit_k_max       22
_diffrn_reflns_limit_k_min       -19
_diffrn_reflns_limit_l_max       8
_diffrn_reflns_limit_l_min       -7
_diffrn_reflns_number            4345
_diffrn_reflns_theta_full        25.99
_diffrn_reflns_theta_max         25.99
_diffrn_reflns_theta_min         2.45
_exptl_absorpt_coefficient_mu    0.068
_exptl_absorpt_correction_T_max  0.9932
_exptl_absorpt_correction_T_min  0.9765
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   sadabs
_exptl_crystal_colour            colorless
_exptl_crystal_density_diffrn    1.211
_exptl_crystal_description       plate
_exptl_crystal_F_000             440
_exptl_crystal_size_max          0.35
_exptl_crystal_size_mid          0.35
_exptl_crystal_size_min          0.10
_refine_diff_density_max         0.136
_refine_diff_density_min         -0.148
_refine_diff_density_rms         0.027
_refine_ls_abs_structure_details 'Flack H D (1983), Acta Cryst. A39, 876-881'
_refine_ls_abs_structure_Flack   -5(10)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.064
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     169
_refine_ls_number_reflns         1805
_refine_ls_number_restraints     1
_refine_ls_restrained_S_all      1.064
_refine_ls_R_factor_all          0.0460
_refine_ls_R_factor_gt           0.0394
_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^)+(0.0600P)^2^+0.0000P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0983
_refine_ls_wR_factor_ref         0.1021
_reflns_number_gt                1590
_reflns_number_total             1805
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            jo2006818_si_005.cif
_cod_data_source_block           beck10
_cod_original_cell_volume        1131.7(9)
_cod_database_code               4026426