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_4026425
_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            'C12 H12'
_chemical_formula_weight         156.22
_chemical_name_common            2,6-dimethylnaphthalene
_space_group_IT_number           61
_symmetry_cell_setting           orthorhombic
_symmetry_Int_Tables_number      61
_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
_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                   7.3229(18)
_cell_length_b                   6.0225(15)
_cell_length_c                   19.985(5)
_cell_measurement_temperature    143(1)
_cell_volume                     881.4(4)
_computing_data_collection       'Bruker APEX2'
_computing_data_reduction        'Bruker SAINT'
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 2008)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 2008)'
_diffrn_ambient_temperature      143(1)
_diffrn_measured_fraction_theta_full 0.994
_diffrn_measured_fraction_theta_max 0.994
_diffrn_measurement_device       'CCD Area Detector'
_diffrn_measurement_device_type  'Bruker APEXII'
_diffrn_measurement_method       'phi and omega scans'
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'sealed tube'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0328
_diffrn_reflns_av_sigmaI/netI    0.0155
_diffrn_reflns_limit_h_max       8
_diffrn_reflns_limit_h_min       -8
_diffrn_reflns_limit_k_max       7
_diffrn_reflns_limit_k_min       -7
_diffrn_reflns_limit_l_max       23
_diffrn_reflns_limit_l_min       -24
_diffrn_reflns_number            9190
_diffrn_reflns_theta_full        25.35
_diffrn_reflns_theta_max         25.35
_diffrn_reflns_theta_min         2.04
_exptl_absorpt_coefficient_mu    0.066
_exptl_absorpt_correction_T_max  1.0000
_exptl_absorpt_correction_T_min  0.8890
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   '(SADABS; Sheldrick, 2007)'
_exptl_crystal_density_diffrn    1.177
_exptl_crystal_F_000             336
_exptl_crystal_size_max          0.28
_exptl_crystal_size_mid          0.25
_exptl_crystal_size_min          0.005
_refine_diff_density_max         0.176
_refine_diff_density_min         -0.127
_refine_diff_density_rms         0.034
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.059
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     80
_refine_ls_number_reflns         804
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.059
_refine_ls_R_factor_all          0.0495
_refine_ls_R_factor_gt           0.0385
_refine_ls_shift/su_max          0.003
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0524P)^2^+0.3324P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1026
_refine_ls_wR_factor_ref         0.1106
_reflns_number_gt                663
_reflns_number_total             804
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            jo2006818_si_003.cif
_cod_data_source_block           shelxl
_cod_original_sg_symbol_H-M      'P b c a '
_cod_database_code               4026425