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_7017871
_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         'C18 H31 Cl N O Ta'
_chemical_formula_sum            'C18 H31 Cl N O Ta'
_chemical_formula_weight         493.84
_chemical_name_common
;
(eta5-pentamethylcyclopendienyl)(oxo)(eta2-N-isopropyl(tert-
butyl)iminoacyl) tantalum
;
_chemical_name_systematic
;
(eta5-pentamethylcyclopendienyl)(oxo)(eta2-N-isopropyl(tert-butyl)iminoacyl)
tantalum
;
_space_group_IT_number           14
_symmetry_cell_setting           monoclinic
_symmetry_space_group_name_Hall  '-P 2yn'
_symmetry_space_group_name_H-M   'P 1 21/n 1'
_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                 108.886(2)
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   8.9863(4)
_cell_length_b                   19.3004(9)
_cell_length_c                   11.7122(5)
_cell_measurement_temperature    100.0(2)
_cell_measurement_theta_max      30.151
_cell_measurement_theta_min      2.618
_cell_volume                     1922.00(15)
_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      100.0(2)
_diffrn_measured_fraction_theta_full 0.996
_diffrn_measured_fraction_theta_max 0.996
_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  0.0279
_diffrn_reflns_av_sigmaI/netI    0.0264
_diffrn_reflns_limit_h_max       12
_diffrn_reflns_limit_h_min       -12
_diffrn_reflns_limit_k_max       25
_diffrn_reflns_limit_k_min       -27
_diffrn_reflns_limit_l_max       16
_diffrn_reflns_limit_l_min       -16
_diffrn_reflns_number            21963
_diffrn_reflns_theta_full        30.15
_diffrn_reflns_theta_max         30.15
_diffrn_reflns_theta_min         2.11
_exptl_absorpt_coefficient_mu    5.860
_exptl_absorpt_correction_T_max  0.3097
_exptl_absorpt_correction_T_min  0.1535
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   'SADABS (Sheldrick, 2008)'
_exptl_crystal_colour            colorless
_exptl_crystal_density_diffrn    1.707
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       prism
_exptl_crystal_F_000             976
_exptl_crystal_size_max          0.5
_exptl_crystal_size_mid          0.4
_exptl_crystal_size_min          0.2
_refine_diff_density_max         1.540
_refine_diff_density_min         -1.124
_refine_diff_density_rms         0.105
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.038
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     209
_refine_ls_number_reflns         5671
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.038
_refine_ls_R_factor_all          0.0258
_refine_ls_R_factor_gt           0.0199
_refine_ls_shift/su_max          0.034
_refine_ls_shift/su_mean         0.001
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0208P)^2^+1.5622P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0464
_refine_ls_wR_factor_ref         0.0483
_reflns_number_gt                4970
_reflns_number_total             5671
_reflns_threshold_expression     >2\s(I)
_cod_data_source_file            c1dt11595b.txt
_cod_data_source_block           ls182_0m
_cod_depositor_comments
;
The following automatic conversions were performed:

'_symmetry_cell_setting' value 'Monoclinic' changed to 'monoclinic'
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_cell_volume        1921.99(15)
_cod_original_sg_symbol_H-M      P21/n
_cod_database_code               7017871