[{Cp~2~(^<i>t^</i>BuSe)Nb}~2~<i>E</i>] (<i>E</i> = O and Se) with bridging oxide or selenide ligands
Hector, Andrew L.; Jura, Marek; Levason, William; Reid, Gillian; Reid, Stuart D.; Webster, Michael; Acta Crystallographica Section C 64 (2008) m321–m323; doi:10.1107/S0108270108025055

data_2016793
_publ_section_title
;
 [{Cp~2~(^<i>t^</i>BuSe)Nb}~2~<i>E</i>] (<i>E</i> = O and Se) with
 bridging oxide or selenide ligands
;
_journal_coeditor_code           BM3060
_journal_issue                   10
_journal_name_full               'Acta Crystallographica Section C'
_journal_page_first              m321
_journal_page_last               m323
_journal_paper_doi               10.1107/S0108270108025055
_journal_volume                  64
_journal_year                    2008
_chemical_formula_iupac          '[Nb2 (C5 H5)4 (C4 H9 Se)2 Se]'
_chemical_formula_moiety         'C28 H38 Nb2 Se3'
_chemical_formula_structural     '[Nb2 (C5 H5)4 (C4 H9 Se)2 Se]'
_chemical_formula_sum            'C28 H38 Nb2 Se3'
_chemical_formula_weight         797.28
_chemical_name_systematic
;
\m-selenido-bis[(tert-butylselenolato)bis(\h^5^-cyclopentadienyl)niobium(IV)]
;
_space_group_IT_number           15
_symmetry_cell_setting           monoclinic
_symmetry_space_group_name_Hall  '-C 2yc'
_symmetry_space_group_name_H-M   'C 1 2/c 1'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_audit_creation_method           'SHELXL97 + hand edit'
_cell_angle_alpha                90.00
_cell_angle_beta                 121.29(2)
_cell_angle_gamma                90.00
_cell_formula_units_Z            8
_cell_length_a                   31.583(8)
_cell_length_b                   7.9548(15)
_cell_length_c                   26.520(7)
_cell_measurement_reflns_used    10429
_cell_measurement_temperature    120(2)
_cell_measurement_theta_max      27.48
_cell_measurement_theta_min      2.91
_cell_volume                     5694(3)
_computing_cell_refinement
;
COLLECT (Nonius, 1998) and DENZO (Otwinowski & Minor, 1997)
;
_computing_data_collection
;
COLLECT (Nonius, 1998) and DENZO (Otwinowski & Minor, 1997)
;
_computing_data_reduction
;
COLLECT (Nonius, 1998) and DENZO (Otwinowski & Minor, 1997)
;
_computing_molecular_graphics    'ORTEPII (Johnson, 1976)'
_computing_publication_material  'SHELXL97 (Sheldrick, 2008)'
_computing_structure_refinement  'SHELXL97 (Sheldrick, 2008)'
_computing_structure_solution    'SHELXS97 (Sheldrick, 2008)'
_diffrn_ambient_temperature      120(2)
_diffrn_measured_fraction_theta_full 0.993
_diffrn_measured_fraction_theta_max 0.993
_diffrn_measurement_device_type
'Bruker Nonius 95mm CCD camera on \k-goniostat'
_diffrn_measurement_method       '\f and \w scans'
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'Bruker Nonius FR591 rotating anode'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0832
_diffrn_reflns_av_sigmaI/netI    0.0763
_diffrn_reflns_limit_h_max       40
_diffrn_reflns_limit_h_min       -40
_diffrn_reflns_limit_k_max       10
_diffrn_reflns_limit_k_min       -10
_diffrn_reflns_limit_l_max       34
_diffrn_reflns_limit_l_min       -34
_diffrn_reflns_number            31432
_diffrn_reflns_theta_full        27.57
_diffrn_reflns_theta_max         27.57
_diffrn_reflns_theta_min         2.99
_diffrn_standards_number         0
_exptl_absorpt_coefficient_mu    4.656
_exptl_absorpt_correction_T_max  0.7560
_exptl_absorpt_correction_T_min  0.5136
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   '(SADABS; Sheldrick, 2007)'
_exptl_crystal_colour            blue
_exptl_crystal_density_diffrn    1.860
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       block
_exptl_crystal_F_000             3120
_exptl_crystal_size_max          0.12
_exptl_crystal_size_mid          0.09
_exptl_crystal_size_min          0.06
_refine_diff_density_max         0.788
_refine_diff_density_min         -0.817
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.022
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     298
_refine_ls_number_reflns         6538
_refine_ls_number_restraints     1
_refine_ls_restrained_S_all      1.041
_refine_ls_R_factor_all          0.0744
_refine_ls_R_factor_gt           0.0413
_refine_ls_shift/su_max          0.001
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'w = 1/[\s^2^(Fo^2^)+(0.0168P)^2^+15.2700P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0668
_refine_ls_wR_factor_ref         0.0746
_reflns_number_gt                4694
_reflns_number_total             6538
_reflns_threshold_expression     I>2\s(I)
_cod_data_source_file            bm3060.cif
_cod_data_source_block           II
_cod_original_sg_symbol_H-M      'C 2/c'
_cod_database_code               2016793
_cod_database_fobs_code          2016793