Synthesis, Characterization, and Reactions of Isolable (β-Diketiminato)Nb(III) Imido Complexes.
Tomson, Neil C.; Arnold, John; Bergman, Robert G.; Organometallics 29 (2010) 5010–5025; doi:10.1021/om1002528

data_4066028
_publ_section_title
;
 Synthesis, Characterization, and Reactions of Isolable
 (\b-Diketiminato)Nb(III) Imido Complexes.
;
_journal_issue                   21
_journal_name_full               Organometallics
_journal_page_first              5010
_journal_page_last               5025
_journal_paper_doi               10.1021/om1002528
_journal_volume                  29
_journal_year                    2010
_chemical_formula_moiety         'C36 H53 Li N3 Nb O2'
_chemical_formula_sum            'C36 H53 Li N3 Nb O2'
_chemical_formula_weight         659.66
_chemical_name_systematic
; 
 ? 
;
_space_group_IT_number           2
_symmetry_cell_setting           triclinic
_symmetry_space_group_name_Hall  '-P 1'
_symmetry_space_group_name_H-M   'P -1'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_audit_creation_method           SHELXL-97
_cell_angle_alpha                73.0690(10)
_cell_angle_beta                 85.1360(10)
_cell_angle_gamma                74.4610(10)
_cell_formula_units_Z            2
_cell_length_a                   11.4341(5)
_cell_length_b                   12.9987(6)
_cell_length_c                   14.2141(7)
_cell_measurement_reflns_used    9937
_cell_measurement_temperature    141(2)
_cell_measurement_theta_max      50.210
_cell_measurement_theta_min      4.679
_cell_volume                     1947.13(16)
_computing_cell_refinement       'Bruker APEX2 v. 2009.1'
_computing_data_collection       'Bruker APEX2 v. 2009.1'
_computing_data_reduction        'Bruker APEX2 v. 2009.1'
_computing_molecular_graphics    ORTEP-32
_computing_publication_material  CIFTAB
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 2008)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 2008)'
_diffrn_ambient_temperature      141(2)
_diffrn_detector_area_resol_mean 8.366
_diffrn_measured_fraction_theta_full 0.993
_diffrn_measured_fraction_theta_max 0.993
_diffrn_measurement_device_type  'BRUKER APEX-I CCD'
_diffrn_measurement_method       '\f and \w 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  0.0759
_diffrn_reflns_av_sigmaI/netI    0.0608
_diffrn_reflns_limit_h_max       13
_diffrn_reflns_limit_h_min       -13
_diffrn_reflns_limit_k_max       15
_diffrn_reflns_limit_k_min       -15
_diffrn_reflns_limit_l_max       17
_diffrn_reflns_limit_l_min       -17
_diffrn_reflns_number            40569
_diffrn_reflns_theta_full        25.37
_diffrn_reflns_theta_max         25.37
_diffrn_reflns_theta_min         1.50
_exptl_absorpt_coefficient_mu    0.339
_exptl_absorpt_correction_T_max  0.9799
_exptl_absorpt_correction_T_min  0.9572
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   SADABS
_exptl_crystal_colour            red
_exptl_crystal_density_diffrn    1.125
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       block
_exptl_crystal_F_000             700
_exptl_crystal_size_max          0.13
_exptl_crystal_size_mid          0.12
_exptl_crystal_size_min          0.06
_platon_squeeze_details
;
Squeeze was used to remove one highly disordered molecule of 
dichloromethane.  The co-crystallized solvent was well-separated 
from the Nb complex, and its removal had negligible impact on the 
bonding within the remaining structure. 
;
_refine_diff_density_max         0.805
_refine_diff_density_min         -0.689
_refine_diff_density_rms         0.073
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.063
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     403
_refine_ls_number_reflns         7101
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.063
_refine_ls_R_factor_all          0.0638
_refine_ls_R_factor_gt           0.0485
_refine_ls_shift/su_max          0.001
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0613P)^2^+0.0000P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1134
_refine_ls_wR_factor_ref         0.1206
_reflns_number_gt                5637
_reflns_number_total             7101
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            om1002528_si_001.cif
_cod_data_source_block           '[(BDI)(CO)Nb(NtBu)(C(Me)OLi)]2'
_cod_database_code               4066028