N-N Bond Cleavage of Mid-Valent Ta(IV) Hydrazido and Hydrazidium Complexes Relevant to the Schrock Cycle for Dinitrogen Fixation
Andrew J. Keane; Peter Y. Zavalij; Lawrence R. Sita; Journal of the American Chemical Society 135 (2013) 9580–9583; doi:10.1021/ja402804k

data_4120015
_publ_section_title
;
 N-N Bond Cleavage of Mid-Valent Ta(IV) Hydrazido and Hydrazidium
 Complexes Relevant to the Schrock Cycle for Dinitrogen Fixation
;
_journal_name_full               'Journal of the American Chemical Society'
_journal_page_first              9580
_journal_page_last               9583
_journal_paper_doi               10.1021/ja402804k
_journal_volume                  135
_journal_year                    2013
_chemical_absolute_configuration ad
_chemical_formula_moiety         'C38 H70 N8 Ta2'
_chemical_formula_sum            'C38 H70 N8 Ta2'
_chemical_formula_weight         1000.92
_chemical_name_common            Ta-complex
_chemical_name_systematic
;
Ta-complex, AK-750
;
_space_group_crystal_system      tetragonal
_space_group_IT_number           92
_space_group_name_Hall           'P 4abw 2nw'
_space_group_name_H-M_alt        'P 41 21 2'
_symmetry_cell_setting           tetragonal
_symmetry_space_group_name_Hall  'P 4abw 2nw'
_symmetry_space_group_name_H-M   'P 41 21 2'
_atom_sites_solution_hydrogens   difmap
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_audit_creation_method           'SHELXL-2012 & ZCIF'
_cell_angle_alpha                90
_cell_angle_beta                 90
_cell_angle_gamma                90
_cell_formula_units_Z            4
_cell_length_a                   11.3498(6)
_cell_length_b                   11.3498(6)
_cell_length_c                   31.8364(17)
_cell_measurement_reflns_used    34213
_cell_measurement_temperature    150(2)
_cell_measurement_theta_max      31.8
_cell_measurement_theta_min      2.2
_cell_volume                     4101.1(4)
_computing_cell_refinement       Apex2
_computing_data_collection       'Apex2 (Bruker, 2010)'
_computing_data_reduction        'Apex2, Saint'
_computing_molecular_graphics    'XSHEL (Bruker, 2004)'
_computing_publication_material  'Apex2, SHELXL-2012'
_computing_structure_refinement  'ShelXL-2012 (Sheldrick, 2012)'
_computing_structure_solution    'ShelXS-97 (Sheldrick, 2008)'
_diffrn_ambient_temperature      150(2)
_diffrn_detector                 'CCD area detector'
_diffrn_detector_area_resol_mean 8.333
_diffrn_measured_fraction_theta_full 1.000
_diffrn_measured_fraction_theta_max 1.000
_diffrn_measurement_device_type  'Bruker Smart Apex II diffractometer'
_diffrn_measurement_method       '\f and \w scans'
_diffrn_measurement_specimen_support 'MiTeGen loop'
_diffrn_orient_matrix_type       standard
_diffrn_orient_matrix_UB_11      0.0579710
_diffrn_orient_matrix_UB_12      0.0608720
_diffrn_orient_matrix_UB_13      0.0094184
_diffrn_orient_matrix_UB_21      -0.0580562
_diffrn_orient_matrix_UB_22      0.0635051
_diffrn_orient_matrix_UB_23      -0.0067351
_diffrn_orient_matrix_UB_31      -0.0321015
_diffrn_orient_matrix_UB_32      -0.0049825
_diffrn_orient_matrix_UB_33      0.0291976
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0268
_diffrn_reflns_av_unetI/netI     0.0133
_diffrn_reflns_Laue_measured_fraction_full 1.000
_diffrn_reflns_Laue_measured_fraction_max 1.000
_diffrn_reflns_limit_h_max       15
_diffrn_reflns_limit_h_min       -15
_diffrn_reflns_limit_k_max       15
_diffrn_reflns_limit_k_min       -15
_diffrn_reflns_limit_l_max       44
_diffrn_reflns_limit_l_min       -44
_diffrn_reflns_number            54593
_diffrn_reflns_point_group_measured_fraction_full 1.000
_diffrn_reflns_point_group_measured_fraction_max 1.000
_diffrn_reflns_theta_full        26.000
_diffrn_reflns_theta_max         29.999
_diffrn_reflns_theta_min         1.905
_diffrn_source                   'sealed tube'
_exptl_absorpt_coefficient_mu    5.368
_exptl_absorpt_correction_T_max  0.211
_exptl_absorpt_correction_T_min  0.144
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   'SADABS (Sheldrick, 2008)'
_exptl_crystal_colour            yellow
_exptl_crystal_density_diffrn    1.621
_exptl_crystal_description       prism
_exptl_crystal_F_000             2000
_exptl_crystal_size_max          0.34
_exptl_crystal_size_mid          0.29
_exptl_crystal_size_min          0.29
_refine_diff_density_max         0.720
_refine_diff_density_min         -0.443
_refine_diff_density_rms         0.062
_refine_ls_abs_structure_details
;
 Flack x determined using 2432 quotients [(I+)-(I-)]/[(I+)+(I-)]
 (Parsons and Flack (2004), Acta Cryst. A60, s61).
;
_refine_ls_abs_structure_Flack   -0.013(3)
_refine_ls_extinction_coef       0.00031(2)
_refine_ls_extinction_expression Fc^*^=kFc[1+0.001xFc^2^\l^3^/sin(2\q)]^-1/4^
_refine_ls_extinction_method     SHELXL
_refine_ls_goodness_of_fit_ref   1.000
_refine_ls_hydrogen_treatment    refU
_refine_ls_matrix_type           full
_refine_ls_number_parameters     243
_refine_ls_number_reflns         5986
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.000
_refine_ls_R_factor_all          0.0145
_refine_ls_R_factor_gt           0.0139
_refine_ls_shift/su_max          0.003
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
;
 w=1/[\s^2^(Fo^2^)+(0.0100P)^2^+4.7100P]
 where P=(Fo^2^+2Fc^2^)/3
;
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0312
_refine_ls_wR_factor_ref         0.0314
_reflns_Friedel_coverage         0.710
_reflns_Friedel_fraction_full    1.000
_reflns_Friedel_fraction_max     1.000
_reflns_number_gt                5882
_reflns_number_total             5986
_reflns_threshold_expression     'I > 2\s(I)'
_iucr_refine_instructions_details 'See _shelx_res_file'
_cod_data_source_file            ja402804k_si_007.cif
_cod_data_source_block           2442
_cod_original_cell_volume        4101.1(5)
_cod_database_code               4120015
_shelx_estimated_absorpt_t_min   0.263
_shelx_estimated_absorpt_t_max   0.305