The synthesis of half-sandwich bis(pentafluorophenyl)boryl-substituted cyclopentadienyl zirconium, niobium and tantalum complexes and the isolation and molecular structure of a zwitterionic niobocene
Lancaster, Simon J.; Hughes, David L.; Dalton Transactions  (2003) 1779–; doi:10.1039/b300552f

data_7012732
_publ_section_title
;
 The synthesis of half-sandwich bis(pentafluorophenyl)boryl-substituted
 cyclopentadienyl zirconium, niobium and tantalum complexes and the
 isolation and molecular structure of a zwitterionic niobocene
;
_journal_issue                   9
_journal_name_full               'Dalton Transactions'
_journal_page_first              1779
_journal_paper_doi               10.1039/b300552f
_journal_year                    2003
_chemical_formula_moiety         'C25 H17 B Cl3 F10 Nb Si, C7 H8'
_chemical_formula_structural     '[Nb Cl2 (C5H4SiMe3) {C5H4B(Cl)(C6F5)2}].tol'
_chemical_formula_sum            'C32 H25 B Cl3 F10 Nb Si'
_chemical_formula_weight         837.68
_chemical_name_common            'Complex 9a, ref. 27'
_space_group_IT_number           14
_symmetry_cell_setting           monoclinic
_symmetry_Int_Tables_number      14
_symmetry_space_group_name_Hall  '-P 2ybc'
_symmetry_space_group_name_H-M   'P 1 21/c 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                 110.45(1)
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   13.801(1)
_cell_length_b                   15.892(1)
_cell_length_c                   15.892(1)
_cell_measurement_temperature    140(1)
_cell_volume                     3265.9(4)
_computing_cell_refinement       'DENZO/CELL (Otwinowski and Minor, 1985)'
_computing_data_collection       'MSC R-Axis-II control software'
_computing_data_reduction
'DENZO, SCALEPACK (Otwinowski and Minor, 1985)'
_computing_molecular_graphics    'ORTEP (Johnson, 1971)'
_computing_publication_material  'SHELXL (Sheldrick, 1997)'
_computing_structure_refinement  'SHELXL (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS (Sheldrick, 1997)'
_diffrn_ambient_temperature      140(1)
_diffrn_measured_fraction_theta_full 0.988
_diffrn_measured_fraction_theta_max 0.988
_diffrn_measurement_device       'Rigaku R-Axis-IIc'
_diffrn_measurement_method       'image-plate oscillation photos'
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'rotating anode'
_diffrn_radiation_type           Mo-K\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0346
_diffrn_reflns_av_sigmaI/netI    0.0372
_diffrn_reflns_limit_h_max       16
_diffrn_reflns_limit_h_min       -16
_diffrn_reflns_limit_k_max       18
_diffrn_reflns_limit_k_min       -18
_diffrn_reflns_limit_l_max       19
_diffrn_reflns_limit_l_min       -19
_diffrn_reflns_number            18703
_diffrn_reflns_theta_full        25.43
_diffrn_reflns_theta_max         25.43
_diffrn_reflns_theta_min         2.03
_diffrn_standards_decay_%        0
_exptl_absorpt_coefficient_mu    0.732
_exptl_absorpt_correction_type   'not applied'
_exptl_crystal_colour            'deep red'
_exptl_crystal_density_diffrn    1.704
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       parallelipiped
_exptl_crystal_F_000             1672
_exptl_crystal_size_max          0.35
_exptl_crystal_size_mid          0.33
_exptl_crystal_size_min          0.25
_refine_diff_density_max         0.392
_refine_diff_density_min         -0.844
_refine_diff_density_rms         0.072
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.064
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     434
_refine_ls_number_reflns         5959
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.064
_refine_ls_R_factor_all          0.0362
_refine_ls_R_factor_gt           0.0326
_refine_ls_shift/su_max          0.001
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0600P)^2^+0.264P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0874
_refine_ls_wR_factor_ref         0.0890
_reflns_number_gt                5347
_reflns_number_total             5959
_reflns_threshold_expression     I>2sigma(I)
_cod_data_source_file            b300552f.txt
_cod_data_source_block           simonl7
_cod_original_sg_symbol_H-M      'P 21/c'
_cod_database_code               7012732