Niobium- and tantalum-benzamidinato complexes with trimethylphosphine, imido, or η-cyclopentadienyl derivatives
Chen, Chi-Tien; Doerrer, Linda H.; Williams, V. Cliff; Green, Malcolm L. H.; Journal of the Chemical Society, Dalton Transactions  (2000) 967–; doi:10.1039/a909333h

data_7009203
_publ_section_title
;
 Niobium- and tantalum-benzamidinato complexes with trimethylphosphine,
 imido, or \h-cyclopentadienyl derivatives
;
_journal_issue                   6
_journal_name_full
'Journal of the Chemical Society, Dalton Transactions'
_journal_page_first              967
_journal_paper_doi               10.1039/a909333h
_journal_year                    2000
_chemical_compound_source
;

?

;
_chemical_formula_moiety         'C22 H41 Cl4 N2 Si2 Ta'
_chemical_formula_sum            'C22 H41 Cl4 N2 Si2 Ta'
_chemical_formula_weight         712.52
_chemical_melting_point          ?
_chemical_name_systematic
;

?

;
_space_group_IT_number           29
_symmetry_cell_setting           orthorhombic
_symmetry_space_group_name_Hall  'P 2c -2ac'
_symmetry_space_group_name_H-M   'P c a 21'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     direct
_cell_angle_alpha                90.
_cell_angle_beta                 90.
_cell_angle_gamma                90.
_cell_formula_units_Z            8
_cell_length_a                   19.289(4)
_cell_length_b                   15.548(2)
_cell_length_c                   20.389(4)
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_cell_measurement_temperature    150
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_cell_measurement_theta_min      0
_cell_volume                     6114.8(19)
_diffrn_ambient_temperature      150
_diffrn_measured_fraction_theta_max 1.000
_diffrn_measurement_method       \wA
_diffrn_radiation_type           'Mo K\a'
_diffrn_radiation_wavelength     0.71069
_diffrn_reflns_av_R_equivalents  0.00
_diffrn_reflns_limit_h_max       24
_diffrn_reflns_limit_h_min       0
_diffrn_reflns_limit_k_max       19
_diffrn_reflns_limit_k_min       0
_diffrn_reflns_limit_l_max       25
_diffrn_reflns_limit_l_min       0
_diffrn_reflns_number            6432
_diffrn_reflns_theta_max         26.57
_diffrn_reflns_theta_min         0.00
_diffrn_standards_decay_%        0.00
_diffrn_standards_interval_count 0
_diffrn_standards_interval_time  0
_diffrn_standards_number         0
_exptl_absorpt_coefficient_mu    4.00
_exptl_absorpt_correction_T_max  0.37
_exptl_absorpt_correction_T_min  0.36
_exptl_absorpt_correction_type   refdelf
_exptl_absorpt_process_details
'refined from delta-F (Walker & Stuart , 1983)'
_exptl_crystal_colour            ' yellow '
_exptl_crystal_density_diffrn    1.55
_exptl_crystal_density_meas      ?
_exptl_crystal_description       ' triangular '
_exptl_crystal_F_000             2843.70
_exptl_crystal_size_max          0.40
_exptl_crystal_size_mid          0.35
_exptl_crystal_size_min          0.25
_refine_diff_density_max         0.91
_refine_diff_density_min         -0.59
_refine_ls_extinction_method     None
_refine_ls_goodness_of_fit_obs   1.0262
_refine_ls_hydrogen_treatment    noref
_refine_ls_matrix_type           full
_refine_ls_number_parameters     559
_refine_ls_number_reflns         5903
_refine_ls_R_factor_obs          0.0243
_refine_ls_shift/su_max          0.000988
_refine_ls_structure_factor_coef F
_refine_ls_weighting_details
;

 Chebychev polynomial with   3 parameters (Carruthers & Watkin, 1979)

 1.04 0.433 0.769

;
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_obs         0.0281
_reflns_limit_h_max              24
_reflns_limit_h_min              0
_reflns_limit_k_max              19
_reflns_limit_k_min              0
_reflns_limit_l_max              25
_reflns_limit_l_min              0
_reflns_number_observed          5903
_reflns_number_total             6889
_reflns_observed_criterion       >3.00\s(I)
_cod_data_source_file            a909333h.txt
_cod_data_source_block           2
_cod_depositor_comments
;
The following automatic conversions were performed:
'_symmetry_cell_setting' value 'Orthorhombic ' changed to 'orthorhombic'
according to '/home/adriana/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_enum 1555 2011-01-17 13:19:09Z saulius 

The following automatic conversions were performed:

'_chemical_melting_point' value 'not measured' was changed to '?' -
the value is undefined or not given.

Automatic conversion script
Id: cif_fix_values 1569 2011-02-09 13:29:24Z adriana 
;
_cod_original_cell_volume        6114.8(5)
_cod_original_sg_symbol_H-M      'P c a 21 '
_cod_database_code               7009203