Dinitrogen Activation at Ambient Temperatures: New Modes of H2 and PhSiH3 Additions for an "End-On-Bridged" [Ta(IV)]2(μ-η1:η1-N2) Complex and for the Bis(μ-nitrido) [Ta(V)(μ-N)]2 Product Derived from Facile N\τbN Bond Cleavage
Masakazu Hirotsu; Philip P. Fontaine; Albert Epshteyn; Lawrence R. Sita; Journal of the American Chemical Society 129 (2007) 9284–9285; doi:10.1021/ja072248v

data_4109738
_publ_section_title
;
 Dinitrogen Activation at Ambient Temperatures: New Modes of H2 and PhSiH3
 Additions for an "End-On-Bridged" [Ta(IV)]2(\m-\h1:\h1-N2) Complex and
 for the Bis(\m-nitrido) [Ta(V)(\m-N)]2 Product Derived from Facile N\\tbN
 Bond Cleavage
;
_journal_name_full               'Journal of the American Chemical Society'
_journal_page_first              9284
_journal_page_last               9285
_journal_paper_doi               10.1021/ja072248v
_journal_volume                  129
_journal_year                    2007
_chemical_formula_moiety         'C42 H72 N6 Si Ta2'
_chemical_formula_sum            'C42 H72 N6 Si Ta2'
_chemical_formula_weight         1051.05
_chemical_name_systematic
;
Ditantalum mu-nitrogen hydrogen complex
;
_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 & ZCIF'
_cell_angle_alpha                97.2000(10)
_cell_angle_beta                 99.5150(10)
_cell_angle_gamma                95.8360(10)
_cell_formula_units_Z            2
_cell_length_a                   10.6823(8)
_cell_length_b                   10.9599(8)
_cell_length_c                   20.1009(15)
_cell_measurement_reflns_used    7914
_cell_measurement_temperature    220(2)
_cell_measurement_theta_max      26.2
_cell_measurement_theta_min      2.3
_cell_volume                     2284.6(3)
_computing_cell_refinement       'SAINT (Bruker, 1999)'
_computing_data_collection       'SMART (Bruker, 1999)'
_computing_data_reduction        SAINT
_computing_molecular_graphics    'XSHEL (Bruker, 1999)'
_computing_publication_material  SHELXL-97
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1990)'
_diffrn_ambient_temperature      220(2)
_diffrn_detector                 'CCD area detector'
_diffrn_detector_area_resol_mean 8.33
_diffrn_detector_type            'Bruker Smart1000'
_diffrn_measured_fraction_theta_full 0.996
_diffrn_measured_fraction_theta_max 0.996
_diffrn_measurement_details      366,366,366,402
_diffrn_measurement_device_type  'three-circle diffractometer'
_diffrn_measurement_method       '\w and \f scans'
_diffrn_measurement_specimen_support 'catcus needle'
_diffrn_orient_matrix_type       standard
_diffrn_orient_matrix_UB_11      0.0889654
_diffrn_orient_matrix_UB_12      -0.0218748
_diffrn_orient_matrix_UB_13      0.0015615
_diffrn_orient_matrix_UB_21      0.0266788
_diffrn_orient_matrix_UB_22      0.0502543
_diffrn_orient_matrix_UB_23      0.0462193
_diffrn_orient_matrix_UB_31      -0.0229379
_diffrn_orient_matrix_UB_32      -0.0747550
_diffrn_orient_matrix_UB_33      0.0214564
_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  0.0352
_diffrn_reflns_av_sigmaI/netI    0.0425
_diffrn_reflns_limit_h_max       12
_diffrn_reflns_limit_h_min       -12
_diffrn_reflns_limit_k_max       12
_diffrn_reflns_limit_k_min       -13
_diffrn_reflns_limit_l_max       23
_diffrn_reflns_limit_l_min       -23
_diffrn_reflns_number            21081
_diffrn_reflns_theta_full        25.00
_diffrn_reflns_theta_max         25.00
_diffrn_reflns_theta_min         2.54
_diffrn_source_current           40
_diffrn_source_voltage           50
_diffrn_standards_decay_%        0
_exptl_absorpt_coefficient_mu    4.846
_exptl_absorpt_correction_T_max  0.824
_exptl_absorpt_correction_T_min  0.653
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   'SADABS (Sheldrick, 1996)'
_exptl_crystal_colour            colorless
_exptl_crystal_density_diffrn    1.528
_exptl_crystal_density_method    not-measured
_exptl_crystal_description       needle
_exptl_crystal_F_000             1052
_exptl_crystal_id
;
;
_exptl_crystal_size_max          0.150
_exptl_crystal_size_mid          0.075
_exptl_crystal_size_min          0.040
_refine_diff_density_max         1.894
_refine_diff_density_min         -0.859
_refine_diff_density_rms         0.108
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.001
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     505
_refine_ls_number_reflns         8008
_refine_ls_number_restraints     40
_refine_ls_restrained_S_all      1.003
_refine_ls_R_factor_all          0.0458
_refine_ls_R_factor_gt           0.0264
_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^)+(0.0173P)^2^+2.95P], P=(max(Fo^2^,0)+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0546
_refine_ls_wR_factor_ref         0.0599
_reflns_number_gt                6154
_reflns_number_total             8008
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            ja072248vsi20070519_015559.cif
_cod_data_source_block           cmpd7
_cod_database_code               4109738