Soft diphosphine and diarsine complexes of niobium(v) and tantalum(v) fluorides: synthesis, properties, structures and comparisons with the corresponding chlorides.
Levason, William; Light, Mark E.; Reid, Gillian; Zhang, Wenjian; Dalton transactions (Cambridge, England : 2003) 43 (2014) 9557–9566; doi:10.1039/c4dt01029a

data_7030790
_publ_section_title
;
 Soft diphosphine and diarsine complexes of niobium(v) and tantalum(v)
 fluorides: synthesis, properties, structures and comparisons with the
 corresponding chlorides.
;
_journal_issue                   25
_journal_name_full
'Dalton transactions (Cambridge, England : 2003)'
_journal_page_first              9557
_journal_page_last               9566
_journal_paper_doi               10.1039/c4dt01029a
_journal_volume                  43
_journal_year                    2014
_chemical_formula_sum            'C20 H32 As4 F10 Nb2'
_chemical_formula_weight         947.96
_space_group_crystal_system      orthorhombic
_space_group_IT_number           70
_space_group_name_Hall           '-F 2uv 2vw'
_space_group_name_H-M_alt        'F d d d'
_symmetry_space_group_name_Hall  '-F 2uv 2vw'
_symmetry_space_group_name_H-M   'F d d d :2'
_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                 90.00
_cell_angle_gamma                90.00
_cell_formula_units_Z            8
_cell_length_a                   12.989(4)
_cell_length_b                   21.329(6)
_cell_length_c                   22.051(6)
_cell_measurement_reflns_used    5669
_cell_measurement_temperature    100(2)
_cell_measurement_theta_max      34.7
_cell_measurement_theta_min      2.1
_cell_volume                     6109(3)
_computing_cell_refinement       'CrystalClear-SM Expert 2.0 r13 (Rigaku, 2011)'
_computing_data_collection       'CrystalClear-SM Expert 2.0 r13 (Rigaku, 2011)'
_computing_data_reduction        'CrystalClear-SM Expert 2.0 r13 (Rigaku, 2011)'
_computing_molecular_graphics    'ORTEP-III (Farrugia, 1997)'
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 2008)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1997)'
_diffrn_ambient_temperature      100(2)
_diffrn_detector                 'CCD plate'
_diffrn_detector_type            'Rigaku HG Saturn724+ (2x2 bin mode)'
_diffrn_measured_fraction_theta_full 0.998
_diffrn_measured_fraction_theta_max 0.998
_diffrn_measurement_device       'Four-circle \k diffractometer'
_diffrn_measurement_device_type  'Rigaku AFC12 '
_diffrn_measurement_method       'Profile data from \w-scans'
_diffrn_radiation_collimation    'Confocal mirrors, VHF VariMax '
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0273
_diffrn_reflns_av_sigmaI/netI    0.0256
_diffrn_reflns_limit_h_max       16
_diffrn_reflns_limit_h_min       -13
_diffrn_reflns_limit_k_max       21
_diffrn_reflns_limit_k_min       -26
_diffrn_reflns_limit_l_max       23
_diffrn_reflns_limit_l_min       -27
_diffrn_reflns_number            5513
_diffrn_reflns_theta_full        25.99
_diffrn_reflns_theta_max         25.99
_diffrn_reflns_theta_min         2.05
_diffrn_source                   'Rotating anode X-ray tube'
_diffrn_source_type              'Rigaku FR-E+ Superbright'
_diffrn_standards_number         0
_exptl_absorpt_coefficient_mu    5.121
_exptl_absorpt_correction_T_max  0.8615
_exptl_absorpt_correction_T_min  0.7838
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details
;
Jacobson, R.A. (1998). REQAB. Private communication to the 
 Rigaku Corporation, Tokyo, Japan. 
;
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    2.061
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       fragment
_exptl_crystal_F_000             3648
_exptl_crystal_size_max          0.05
_exptl_crystal_size_mid          0.04
_exptl_crystal_size_min          0.03
_refine_diff_density_max         2.427
_refine_diff_density_min         -0.926
_refine_diff_density_rms         0.241
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.337
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     99
_refine_ls_number_reflns         1510
_refine_ls_number_restraints     25
_refine_ls_restrained_S_all      1.331
_refine_ls_R_factor_all          0.0564
_refine_ls_R_factor_gt           0.0516
_refine_ls_shift/su_max          0.000
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.1000P)^2^+0.0000P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1595
_refine_ls_wR_factor_ref         0.1708
_reflns_number_gt                1399
_reflns_number_total             1510
_reflns_threshold_expression     >2\s(I)
_cod_data_source_file            c4dt01029a2.cif
_cod_data_source_block           14rwz213
_cod_depositor_comments
'Adding full bibliography for 7030785--7030792.cif.'
_cod_database_code               7030790