Metallapyrimidines and Metallapyrimidiniums from Oxidative Addition of Pyrazolate N‒N Bonds to Niobium(III), Niobium(IV), and Tantalum(IV) Metal Centers and Assessment of Their Aromatic Character
Perera, T. Hiran; Lord, Richard L.; Heeg, Mary Jane; Schlegel, H. Bernhard; Winter, Charles H.; Organometallics 31 (2012) 5971–; doi:10.1021/om300490w

data_4078976
_publ_section_title
;
 Metallapyrimidines and Metallapyrimidiniums from Oxidative Addition of
 Pyrazolate N--N Bonds to Niobium(III), Niobium(IV), and Tantalum(IV)
 Metal Centers and Assessment of Their Aromatic Character
;
_journal_issue                   17
_journal_name_full               Organometallics
_journal_page_first              5971
_journal_paper_doi               10.1021/om300490w
_journal_volume                  31
_journal_year                    2012
_chemical_formula_sum            'C33 H58 Cl N6 Ta'
_chemical_formula_weight         755.25
_chemical_name_systematic
; 
 ? 
;
_space_group_IT_number           19
_symmetry_cell_setting           orthorhombic
_symmetry_space_group_name_Hall  'P 2ac 2ab'
_symmetry_space_group_name_H-M   'P 21 21 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                   10.2318(3)
_cell_length_b                   17.9282(5)
_cell_length_c                   20.2874(6)
_cell_measurement_reflns_used    8121
_cell_measurement_temperature    100(2)
_cell_measurement_theta_max      32.2
_cell_measurement_theta_min      2.5
_cell_volume                     3721.48(19)
_computing_cell_refinement       'Bruker APEX2'
_computing_data_collection       'Bruker APEX2'
_computing_data_reduction        'Bruker APEX2'
_computing_molecular_graphics    SHELXTL-Plus
_computing_publication_material  SHELXL-97
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1990)'
_diffrn_ambient_temperature      100(2)
_diffrn_measured_fraction_theta_full 0.999
_diffrn_measured_fraction_theta_max 0.987
_diffrn_measurement_method       'Bruker APEX2'
_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  0.0450
_diffrn_reflns_av_sigmaI/netI    0.0282
_diffrn_reflns_limit_h_max       15
_diffrn_reflns_limit_h_min       -15
_diffrn_reflns_limit_k_max       26
_diffrn_reflns_limit_k_min       0
_diffrn_reflns_limit_l_max       30
_diffrn_reflns_limit_l_min       0
_diffrn_reflns_number            104878
_diffrn_reflns_theta_full        28.30
_diffrn_reflns_theta_max         32.93
_diffrn_reflns_theta_min         1.52
_exptl_absorpt_coefficient_mu    3.054
_exptl_absorpt_correction_T_max  0.5157
_exptl_absorpt_correction_T_min  0.3979
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   'SADABS, Sheldrick, 1997'
_exptl_crystal_colour            yellow
_exptl_crystal_density_diffrn    1.348
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       fragment
_exptl_crystal_F_000             1552
_exptl_crystal_size_max          0.37
_exptl_crystal_size_mid          0.29
_exptl_crystal_size_min          0.25
_refine_diff_density_max         1.091
_refine_diff_density_min         -0.633
_refine_diff_density_rms         0.074
_refine_ls_abs_structure_details 'Flack H D (1983), Acta Cryst. A39, 876-881'
_refine_ls_abs_structure_Flack   -0.009(3)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   0.989
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     392
_refine_ls_number_reflns         13561
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      0.989
_refine_ls_R_factor_all          0.0209
_refine_ls_R_factor_gt           0.0192
_refine_ls_shift/su_max          0.004
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0190P)^2^+0.8518P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0398
_refine_ls_wR_factor_ref         0.0402
_reflns_number_gt                13098
_reflns_number_total             13561
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            om300490w_si_002.cif
_cod_data_source_block           hirn_(2)
_cod_depositor_comments
;
The following automatic conversions were performed:

'_exptl_absorpt_correction_type' value 'Multi-scan' changed to
'multi-scan' according to the built-in table from CIF Core dictionary
named 'cif_core.dic' version 2.4.1 from 2010-06-29.

Automatic conversion script
Id: cif_fix_values 1715 2011-07-08 13:25:40Z adriana 
;
_cod_original_sg_symbol_H-M      P212121
_cod_database_code               4078976