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_4109737
_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         'C36 H66 N6 Ta2'
_chemical_formula_sum            'C36 H66 N6 Ta2'
_chemical_formula_weight         944.85
_chemical_name_common            'Tantalum nitrogen hydrogen complex'
_chemical_name_systematic        ?
_space_group_IT_number           15
_symmetry_cell_setting           monoclinic
_symmetry_space_group_name_Hall  '-C 2yc'
_symmetry_space_group_name_H-M   'C 1 2/c 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                90.00
_cell_angle_beta                 107.176(3)
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   14.506(3)
_cell_length_b                   14.123(2)
_cell_length_c                   20.514(4)
_cell_measurement_reflns_used    7187
_cell_measurement_temperature    298(2)
_cell_measurement_theta_max      27.7
_cell_measurement_theta_min      2.5
_cell_volume                     4015.2(13)
_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      298(2)
_diffrn_detector                 'CCD area detector'
_diffrn_detector_area_resol_mean 8.33
_diffrn_detector_type            'Bruker Smart1000'
_diffrn_measured_fraction_theta_full 0.999
_diffrn_measured_fraction_theta_max 0.999
_diffrn_measurement_details      186,186,186,726,366
_diffrn_measurement_device_type  'three-circle diffractometer'
_diffrn_measurement_method       '\w and \f scans'
_diffrn_measurement_specimen_support 'covered w/ SuperGlue on cactus needle'
_diffrn_orient_matrix_type       standard
_diffrn_orient_matrix_UB_11      0.0692367
_diffrn_orient_matrix_UB_12      -0.0181702
_diffrn_orient_matrix_UB_13      0.0088189
_diffrn_orient_matrix_UB_21      0.0094207
_diffrn_orient_matrix_UB_22      0.0029236
_diffrn_orient_matrix_UB_23      0.0502570
_diffrn_orient_matrix_UB_31      -0.0180041
_diffrn_orient_matrix_UB_32      -0.0683760
_diffrn_orient_matrix_UB_33      -0.0001792
_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  0.0581
_diffrn_reflns_av_sigmaI/netI    0.0328
_diffrn_reflns_limit_h_max       17
_diffrn_reflns_limit_h_min       -17
_diffrn_reflns_limit_k_max       16
_diffrn_reflns_limit_k_min       -16
_diffrn_reflns_limit_l_max       24
_diffrn_reflns_limit_l_min       -24
_diffrn_reflns_number            25984
_diffrn_reflns_theta_full        25.00
_diffrn_reflns_theta_max         25.00
_diffrn_reflns_theta_min         2.49
_diffrn_source_current           40
_diffrn_source_voltage           50
_diffrn_standards_decay_%        0
_exptl_absorpt_coefficient_mu    5.476
_exptl_absorpt_correction_T_max  0.760
_exptl_absorpt_correction_T_min  0.630
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   'SADABS (Sheldrick, 1996)'
_exptl_crystal_colour            orange
_exptl_crystal_density_diffrn    1.563
_exptl_crystal_density_method    not-measured
_exptl_crystal_description       prism
_exptl_crystal_F_000             1880
_exptl_crystal_id                'Sita/Hirotsu mh098'
_exptl_crystal_size_max          0.14
_exptl_crystal_size_mid          0.08
_exptl_crystal_size_min          0.05
_refine_diff_density_max         1.257
_refine_diff_density_min         -0.744
_refine_diff_density_rms         0.093
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.000
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     213
_refine_ls_number_reflns         3528
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.000
_refine_ls_R_factor_all          0.0359
_refine_ls_R_factor_gt           0.0221
_refine_ls_shift/su_max          0.000
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'w=1/[\s^2^(Fo^2^)+(0.0133P)^2^+9.95P], P=(max(Fo^2^,0)+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0454
_refine_ls_wR_factor_ref         0.0495
_reflns_number_gt                2815
_reflns_number_total             3528
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            ja072248vsi20070329_103526.cif
_cod_data_source_block           cmpd_6
_cod_original_cell_volume        4015.2(12)
_cod_database_code               4109737