Synthesis and reactions of (tert-butylimido)bis(η-cyclopentadienyl)niobium cations: NMR evidence for d0 olefin cations [Nb{(η-C5H5)2}(NtBu)(η-C2H4)][B(C6F5)4] and [Nb{(η-C5H4)CMe2(η-C5H4)}(NtBu)(η-C2H3Me)][B(C6F5)4]
Humphries, Martin J.; Douthwaite, Richard E.; Green, Malcolm L. H.; Journal of the Chemical Society, Dalton Transactions  (2000) 2952–; doi:10.1039/b004062m

data_7009861
_publ_section_title
;
 Synthesis and reactions of
 (tert-butylimido)bis(\h-cyclopentadienyl)niobium cations: NMR evidence
 for d0 olefin cations [Nb{(\h-C5H5)2}(NtBu)(\h-C2H4)][B(C6F5)4] and
 [Nb{(\h-C5H4)CMe2(\h-C5H4)}(NtBu)(\h-C2H3Me)][B(C6F5)4]
;
_journal_issue                   17
_journal_name_full
'Journal of the Chemical Society, Dalton Transactions'
_journal_page_first              2952
_journal_paper_doi               10.1039/b004062m
_journal_year                    2000
_chemical_compound_source
;
?
;
_chemical_formula_moiety         'C18 H28 F3 N Nb O3 P S'
_chemical_formula_sum            'C18 H28 F3 N Nb O3 P S'
_chemical_formula_weight         519.36
_chemical_melting_point          ?
_chemical_name_systematic
;                                                                               
[Nb(eta-C5H5)2(NtBu)(PMe3)][CF3SO3]
;
_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
_cell_angle_alpha                90.
_cell_angle_beta                 92.12(2)
_cell_angle_gamma                90.
_cell_formula_units_Z            4
_cell_length_a                   8.868(1)
_cell_length_b                   18.934(2)
_cell_length_c                   13.641(2)
_cell_measurement_reflns_used    0
_cell_measurement_temperature    0
_cell_measurement_theta_max      0
_cell_measurement_theta_min      0
_cell_volume                     2288.8(5)
_computing_molecular_graphics
;                                                                               
 CAMERON (Watkin, Prout & Pearce,  1996)                                        
;
_computing_publication_material
;                                                                               
CRYSTALS Issue 10 (Watkin, Prout, Carruthers & Betteridge, 1996)                
;
_computing_structure_refinement
;                                                                               
CRYSTALS Issue 10 (Watkin, Prout, Carruthers & Betteridge, 1996)                
;
_computing_structure_solution    'SIR92 (Giacovazzo et al, 1992)'
_diffrn_ambient_temperature      180
_diffrn_measurement_method       \w/2\q
_diffrn_radiation_type           'Mo K\a'
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.032
_diffrn_reflns_limit_h_max       11
_diffrn_reflns_limit_h_min       -11
_diffrn_reflns_limit_k_max       23
_diffrn_reflns_limit_k_min       0
_diffrn_reflns_limit_l_max       16
_diffrn_reflns_limit_l_min       0
_diffrn_reflns_number            11019
_diffrn_reflns_theta_max         26.34
_diffrn_reflns_theta_min         1.62
_diffrn_standards_decay_%        0.00
_diffrn_standards_interval_count 0
_diffrn_standards_interval_time  0
_diffrn_standards_number         0
_exptl_absorpt_coefficient_mu    0.70
_exptl_absorpt_correction_type   none
_exptl_crystal_colour            ' yellow '
_exptl_crystal_density_diffrn    1.51
_exptl_crystal_density_meas      ?
_exptl_crystal_description       ' box '
_exptl_crystal_F_000             1056.18
_exptl_crystal_size_max          0.02
_exptl_crystal_size_mid          0.02
_exptl_crystal_size_min          0.02
_refine_diff_density_max         0.83
_refine_diff_density_min         -0.92
_refine_ls_extinction_method     None
_refine_ls_goodness_of_fit_obs   0.9767
_refine_ls_hydrogen_treatment    noref
_refine_ls_matrix_type           full
_refine_ls_number_parameters     254
_refine_ls_number_reflns         3510
_refine_ls_R_factor_obs          0.0327
_refine_ls_shift/su_max          0.000859
_refine_ls_structure_factor_coef F
_refine_ls_weighting_details
;
 Chebychev polynomial with   3 parameters (Carruthers & Watkin, 1979)
 2.54 0.640 2.06
;
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_obs         0.0396
_reflns_limit_h_max              11
_reflns_limit_h_min              -11
_reflns_limit_k_max              23
_reflns_limit_k_min              0
_reflns_limit_l_max              16
_reflns_limit_l_min              0
_reflns_number_observed          3510
_reflns_number_total             4777
_reflns_observed_criterion       >3.00\s(I)
_cod_data_source_file            b004062m.txt
_cod_data_source_block           compound2
_cod_depositor_comments
;
The following automatic conversions were performed:
'_symmetry_cell_setting' value 'Monoclinic ' changed to 'monoclinic'
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        2288.9(4)
_cod_original_sg_symbol_H-M      'P 1 21/n 1 '
_cod_database_code               7009861