Quantifying the Electron Donor and Acceptor Abilities of the Ketimide Ligands in M(N═C(t)Bu2)4 (M = V, Nb, Ta).
Damon, Peter L.; Liss, Cameron J.; Lewis, Richard A.; Morochnik, Simona; Szpunar, David E.; Telser, Joshua; Hayton, Trevor W.; Inorganic chemistry 54 (2015) 10081–10095; doi:10.1021/acs.inorgchem.5b02017

data_4346717
_publ_section_title
;
 Quantifying the Electron Donor and Acceptor Abilities of the Ketimide
 Ligands in M(N&#x2550;C(t)Bu2)4 (M = V, Nb, Ta).
;
_journal_issue                   20
_journal_name_full               'Inorganic chemistry'
_journal_page_first              10081
_journal_page_last               10095
_journal_paper_doi               10.1021/acs.inorgchem.5b02017
_journal_volume                  54
_journal_year                    2015
_chemical_formula_moiety         'C6 H16 Cl4 N2 Ta'
_chemical_formula_sum            'C6 H16 Cl4 N2 Ta'
_chemical_formula_weight         438.96
_space_group_crystal_system      orthorhombic
_space_group_IT_number           33
_space_group_name_Hall           'P 2c -2n'
_space_group_name_H-M_alt        'P n a 21'
_atom_sites_solution_hydrogens   geom
_audit_creation_method           SHELXL-97
_cell_angle_alpha                90
_cell_angle_beta                 90
_cell_angle_gamma                90
_cell_formula_units_Z            4
_cell_length_a                   14.503(3)
_cell_length_b                   7.4837(14)
_cell_length_c                   11.782(2)
_cell_measurement_temperature    104(2)
_cell_volume                     1278.8(4)
_computing_structure_refinement  'SHELXL-2013 (Sheldrick, 2013)'
_diffrn_ambient_temperature      104(2)
_diffrn_measured_fraction_theta_full 0.996
_diffrn_measured_fraction_theta_max 0.945
_diffrn_measurement_device_type  'Bruker Kappa Apex II'
_diffrn_measurement_method       'Omega scan'
_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  0.0323
_diffrn_reflns_av_unetI/netI     0.0424
_diffrn_reflns_Laue_measured_fraction_full 0.996
_diffrn_reflns_Laue_measured_fraction_max 0.945
_diffrn_reflns_limit_h_max       15
_diffrn_reflns_limit_h_min       -24
_diffrn_reflns_limit_k_max       13
_diffrn_reflns_limit_k_min       -13
_diffrn_reflns_limit_l_max       7
_diffrn_reflns_limit_l_min       -21
_diffrn_reflns_number            9388
_diffrn_reflns_point_group_measured_fraction_full 0.734
_diffrn_reflns_point_group_measured_fraction_max 0.581
_diffrn_reflns_theta_full        25.242
_diffrn_reflns_theta_max         40.775
_diffrn_reflns_theta_min         2.809
_exptl_absorpt_coefficient_mu    9.393
_exptl_absorpt_correction_T_max  0.7480
_exptl_absorpt_correction_T_min  0.5426
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   sadabs
_exptl_crystal_colour            orange
_exptl_crystal_density_diffrn    2.280
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       block
_exptl_crystal_F_000             828
_exptl_crystal_size_max          0.15
_exptl_crystal_size_mid          0.12
_exptl_crystal_size_min          0.10
_exptl_transmission_factor_max   0.7480
_exptl_transmission_factor_min   0.5426
_refine_diff_density_max         3.078
_refine_diff_density_min         -3.057
_refine_diff_density_rms         0.233
_refine_ls_abs_structure_details
;
 Flack x determined using 639 quotients [(I+)-(I-)]/[(I+)+(I-)]
 (Parsons and Flack (2004), Acta Cryst. A60, s61).
;
_refine_ls_abs_structure_Flack   0.483(9)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   0.822
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     122
_refine_ls_number_reflns         4831
_refine_ls_number_restraints     1
_refine_ls_restrained_S_all      0.822
_refine_ls_R_factor_all          0.0573
_refine_ls_R_factor_gt           0.0389
_refine_ls_shift/su_max          0.001
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'w=1/[\s^2^(Fo^2^)+(0.1000P)^2^] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1078
_refine_ls_wR_factor_ref         0.1211
_reflns_Friedel_coverage         0.190
_reflns_Friedel_fraction_full    0.444
_reflns_Friedel_fraction_max     0.192
_reflns_number_gt                3768
_reflns_number_total             4831
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            ic5b02017_si_001.cif
_cod_data_source_block           complex3
_cod_database_code               4346717