51V Magic Angle Spinning NMR Spectroscopy of Keggin Anions [PVnW12-nO40](3+n)-: Effect of Countercation and Vanadium Substitution on Fine Structure Constants
Wenlin Huang; Louis Todaro; Glenn P. A. Yap; Robert Beer; Lynn C. Francesconi; Tatyana Polenova; Journal of the American Chemical Society 126 (2004) 11564–11573; doi:10.1021/ja0475499

data_4112950
_publ_section_title
;
 51V Magic Angle Spinning NMR Spectroscopy of Keggin Anions
 [PVnW12-nO40](3+n)-: Effect of Countercation and Vanadium Substitution on
 Fine Structure Constants
;
_journal_name_full               'Journal of the American Chemical Society'
_journal_page_first              11564
_journal_page_last               11573
_journal_paper_doi               10.1021/ja0475499
_journal_volume                  126
_journal_year                    2004
_chemical_formula_sum            'C2 H20 K2 O52 P V2 W10'
_chemical_formula_weight         2925.73
_chemical_name_systematic
; 
 ? 
;
_space_group_IT_number           145
_symmetry_cell_setting           trigonal
_symmetry_space_group_name_Hall  'P 32'
_symmetry_space_group_name_H-M   'P 32'
_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                120.00
_cell_formula_units_Z            3
_cell_length_a                   19.057(3)
_cell_length_b                   19.057(3)
_cell_length_c                   12.505(3)
_cell_measurement_temperature    295(2)
_cell_volume                     3933.0(13)
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1990)'
_diffrn_ambient_temperature      295(2)
_diffrn_measured_fraction_theta_full 0.998
_diffrn_measured_fraction_theta_max 0.998
_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  0.0000
_diffrn_reflns_av_sigmaI/netI    0.0765
_diffrn_reflns_limit_h_max       24
_diffrn_reflns_limit_h_min       -24
_diffrn_reflns_limit_k_max       20
_diffrn_reflns_limit_k_min       -20
_diffrn_reflns_limit_l_max       15
_diffrn_reflns_limit_l_min       -16
_diffrn_reflns_number            11239
_diffrn_reflns_theta_full        27.45
_diffrn_reflns_theta_max         27.45
_diffrn_reflns_theta_min         2.47
_exptl_absorpt_coefficient_mu    22.474
_exptl_absorpt_correction_T_max  0.6034
_exptl_absorpt_correction_T_min  0.0314
_exptl_crystal_density_diffrn    3.706
_exptl_crystal_F_000             3861
_exptl_crystal_size_max          0.50
_exptl_crystal_size_mid          0.05
_exptl_crystal_size_min          0.03
_refine_diff_density_max         1.057
_refine_diff_density_min         -1.105
_refine_diff_density_rms         0.238
_refine_ls_abs_structure_details 'Flack H D (1983), Acta Cryst. A39, 876-881'
_refine_ls_abs_structure_Flack   0.098(18)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.020
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     629
_refine_ls_number_reflns         11239
_refine_ls_number_restraints     1
_refine_ls_restrained_S_all      1.020
_refine_ls_R_factor_all          0.0609
_refine_ls_R_factor_gt           0.0478
_refine_ls_shift/su_max          0.011
_refine_ls_shift/su_mean         0.001
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0169P)^2^+68.8191P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1049
_refine_ls_wR_factor_ref         0.1118
_reflns_number_gt                9701
_reflns_number_total             11239
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            ja0475499si20040502_022021.cif
_cod_data_source_block           x1434r
_cod_original_cell_volume        3933.0(11)
_cod_database_code               4112950