Neutron and X-ray Diffraction Studies and DFT Calculations of Asymmetric Bis(silyl) Niobocene Hydrides
Dorogov, Konstantin Yu.; Dumont, Elise; Ho, Nam-Nhat; Churakov, Andrei V.; Kuzmina, Lyudmila G.; Poblet, Josep-Maria; Schultz, Arthur J.; Howard, Judith A. K.; Bau, Robert; Lledos, Agusti; Nikonov, Georgii I.; Organometallics 23 (2004) 2845–2847; doi:10.1021/om034239a

data_4062571
_publ_contact_author
; Dr Georgii I. Nikonov
  Department of Chemistry, Moscow State University
  Vorob'evy Gory, Moscow 119899, Russia
;
_publ_section_title
'Neutron and X-ray Diffraction Studies and DFT Calculations of Asymmetric Bis(silyl) Niobocene Hydrides'
_journal_issue                   12
_journal_name_full               Organometallics
_journal_page_first              2845
_journal_page_last               2847
_journal_paper_doi               10.1021/om034239a
_journal_volume                  23
_journal_year                    2004
_chemical_formula_sum            'C14 H24 Br Nb Si2'
_chemical_formula_weight         421.33
_chemical_name_common
;  
(dimethylsilyl)(dimethylbromosilyl)niobocene hydrid 
;
_chemical_name_systematic
;  
bis(cyclopentadienyl)(dimethylsilyl)
(dimethylbromosilyl)(hydrido) niobium (V) 
;
_space_group_IT_number           15
_space_group_name_Hall           '-C 2yc'
_space_group_name_H-M_alt        'C 1 2/c 1'
_symmetry_cell_setting           monoclinic
_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_date             2004-04-16T09:30
_audit_creation_method           SHELXL-97
_audit_update_record
' 2004-04-16T09:30  Initial CIF as created by GSAS2CIF'
_cell_angle_alpha                90.00
_cell_angle_beta                 99.408(2)
_cell_angle_gamma                90.00
_cell_formula_units_Z            8
_cell_length_a                   14.9449(5)
_cell_length_b                   8.9330(3)
_cell_length_c                   26.0528(9)
_cell_measurement_temperature    83(2)
_cell_volume                     3431.3(2)
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1990)'
_diffrn_ambient_temperature      83(2)
_diffrn_measured_fraction_theta_full 0.999
_diffrn_measured_fraction_theta_max 0.999
_diffrn_measurement_device_type  'Bruker SMART'
_diffrn_measurement_method       \w
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'fine-focus sealed tube'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0819
_diffrn_reflns_av_sigmaI/netI    0.0791
_diffrn_reflns_limit_h_max       19
_diffrn_reflns_limit_h_min       -19
_diffrn_reflns_limit_k_max       11
_diffrn_reflns_limit_k_min       -11
_diffrn_reflns_limit_l_max       30
_diffrn_reflns_limit_l_min       -33
_diffrn_reflns_number            12752
_diffrn_reflns_theta_full        27.00
_diffrn_reflns_theta_max         27.00
_diffrn_reflns_theta_min         1.58
_exptl_absorpt_coefficient_mu    3.154
_exptl_absorpt_correction_T_max  0.6665
_exptl_absorpt_correction_T_min  0.5438
_exptl_absorpt_correction_type   multi-scan
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.631
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       block
_exptl_crystal_F_000             1696
_exptl_crystal_size_max          0.22
_exptl_crystal_size_mid          0.16
_exptl_crystal_size_min          0.14
_refine_diff_density_max         1.853
_refine_diff_density_min         -1.143
_refine_diff_density_rms         0.183
_refine_ls_extinction_coef       0.0013(2)
_refine_ls_extinction_expression Fc^*^=kFc[1+0.001xFc^2^\l^3^/sin(2\q)]^-1/4^
_refine_ls_extinction_method     SHELXL
_refine_ls_goodness_of_fit_all   1.43
_refine_ls_goodness_of_fit_ref   1.079
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     167
_refine_ls_number_reflns         3749
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.079
_refine_ls_R_factor_all          0.0993
_refine_ls_R_factor_gt           0.0643
_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^)+(0.0885P)^2^+0.0000P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1529
_refine_ls_wR_factor_ref         0.1649
_reflns_number_gt                2654
_reflns_number_total             3749
_reflns_threshold_expression     I>2\s(I)
_cod_data_source_file            om034239asi20040421_035914-EDITED.cif
_cod_data_source_block           sad
_cod_database_code               4062571