Oxygen extrusion from amidate ligands to generate terminal Ta[double bond, length as m-dash]O units under reducing conditions. How to successfully use amidate ligands in dinitrogen coordination chemistry.
Horrillo-Martinez, Patricia; Patrick, Brian O.; Schafer, Laurel L.; Fryzuk, Michael D.; Dalton transactions (Cambridge, England : 2003) 41 (2012) 1609–1616; doi:10.1039/c1dt11595b

data_7017873
_publ_section_title
;
 Oxygen extrusion from amidate ligands to generate terminal Ta[double
 bond, length as m-dash]O units under reducing conditions. How to
 successfully use amidate ligands in dinitrogen coordination chemistry.
;
_journal_issue                   5
_journal_name_full
'Dalton transactions (Cambridge, England : 2003)'
_journal_page_first              1609
_journal_page_last               1616
_journal_paper_doi               10.1039/c1dt11595b
_journal_volume                  41
_journal_year                    2012
_chemical_formula_moiety         '2(C46 H66 Cl2 N4 O2 Ta2), 3(C7 H8)'
_chemical_formula_sum            'C113 H156 Cl4 N8 O4 Ta4'
_chemical_formula_weight         2556.06
_chemical_name_common
;
(eta5-pentamethylcyclopendienyl)(eta3-N-2,6-
dimethylphenyl(tert-butyl)amidate) (mu-eta1,eta1-dinitrogen)tantalum
;
_chemical_name_systematic
;
(eta5-pentamethylcyclopendienyl)(eta3-N-2,6-dimethylphenyl(tert-butyl)amidate)
(mu-eta1,eta1-dinitrogen)tantalum
;
_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                93.870(10)
_cell_angle_beta                 93.340(10)
_cell_angle_gamma                90.310(10)
_cell_formula_units_Z            2
_cell_length_a                   10.798(2)
_cell_length_b                   18.392(4)
_cell_length_c                   28.086(6)
_cell_measurement_reflns_used    7547
_cell_measurement_temperature    100(2)
_cell_measurement_theta_max      27.8985
_cell_measurement_theta_min      2.5345
_cell_volume                     5555(2)
_computing_cell_refinement       'Bruker SAINT'
_computing_data_collection       'Bruker APEX2'
_computing_data_reduction        'Bruker SAINT'
_computing_molecular_graphics    'Bruker SHELXTL'
_computing_publication_material  'Bruker SHELXTL'
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 2008)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 2008)'
_diffrn_ambient_temperature      100(2)
_diffrn_measured_fraction_theta_full 0.981
_diffrn_measured_fraction_theta_max 0.981
_diffrn_measurement_device_type  'Bruker X8 APEX II'
_diffrn_measurement_method       'area detector'
_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  0.0732
_diffrn_reflns_av_sigmaI/netI    0.0729
_diffrn_reflns_limit_h_max       14
_diffrn_reflns_limit_h_min       -14
_diffrn_reflns_limit_k_max       24
_diffrn_reflns_limit_k_min       -23
_diffrn_reflns_limit_l_max       33
_diffrn_reflns_limit_l_min       -37
_diffrn_reflns_number            105750
_diffrn_reflns_theta_full        28.05
_diffrn_reflns_theta_max         28.05
_diffrn_reflns_theta_min         1.37
_exptl_absorpt_coefficient_mu    4.075
_exptl_absorpt_correction_T_max  0.665
_exptl_absorpt_correction_T_min  0.574
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   'SADABS (Sheldrick, 2008)'
_exptl_crystal_colour            red
_exptl_crystal_density_diffrn    1.528
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       prism
_exptl_crystal_F_000             2564
_exptl_crystal_size_max          0.2
_exptl_crystal_size_mid          0.2
_exptl_crystal_size_min          0.1
_refine_diff_density_max         1.164
_refine_diff_density_min         -0.840
_refine_diff_density_rms         0.151
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   0.995
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     1241
_refine_ls_number_reflns         26492
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      0.995
_refine_ls_R_factor_all          0.0608
_refine_ls_R_factor_gt           0.0356
_refine_ls_shift/su_max          0.005
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0162P)^2^+0.0000P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0681
_refine_ls_wR_factor_ref         0.0764
_reflns_number_gt                19547
_reflns_number_total             26492
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            c1dt11595b.txt
_cod_data_source_block           ls206_7b_ls307r_v2
_cod_depositor_comments
;
The following automatic conversions were performed:

'_symmetry_cell_setting' value 'Triclinic' changed to 'triclinic'
according to /home/saulius/struct/CIF-dictionaries/cif_core.dic
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      P-1
_cod_database_code               7017873