Niobocene hydrides with functionalised silyl ligands. Tuning of interligand hypervalent interactions (IHI) M‒H →Si‒X
Nikonov, Georgii I.; Kuzmina, Lyudmila G.; Howard, Judith A. K.; Journal of the Chemical Society, Dalton Transactions  (2002) 3037–; doi:10.1039/b110998g

data_7011352
_publ_section_title
;
 Niobocene hydrides with functionalised silyl ligands. Tuning of
 interligand hypervalent interactions (IHI) M--H \\rightarrow Si--X
;
_journal_issue                   15
_journal_name_full
'Journal of the Chemical Society, Dalton Transactions'
_journal_page_first              3037
_journal_paper_doi               10.1039/b110998g
_journal_year                    2002
_chemical_formula_moiety         '[Cp2Nb(AlH4)]2'
_chemical_formula_sum            'C10 H14 Al Nb'
_chemical_formula_weight         254.10
_chemical_name_common            'tetrahydraaluminate niobocene dimer'
_chemical_name_systematic
; 
bis[bis(cyclopentadienyl)tetrahydraaluminate niobium(III)] 
;
_space_group_IT_number           14
_symmetry_cell_setting           monoclinic
_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
_cell_angle_alpha                90.00
_cell_angle_beta                 101.01(2)
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   5.894(2)
_cell_length_b                   12.499(2)
_cell_length_c                   14.256(4)
_cell_measurement_temperature    153(2)
_cell_volume                     1030.9(5)
_computing_structure_refinement  'SHELXL-93 (Sheldrick, 1993)'
_computing_structure_solution    'SHELXS-86 (Sheldrick, 1990)'
_diffrn_ambient_temperature      153(2)
_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  0.0311
_diffrn_reflns_av_sigmaI/netI    0.0280
_diffrn_reflns_limit_h_max       7
_diffrn_reflns_limit_h_min       -7
_diffrn_reflns_limit_k_max       16
_diffrn_reflns_limit_k_min       -16
_diffrn_reflns_limit_l_max       13
_diffrn_reflns_limit_l_min       -18
_diffrn_reflns_number            6705
_diffrn_reflns_theta_max         26.50
_diffrn_reflns_theta_min         2.18
_exptl_absorpt_coefficient_mu    1.196
_exptl_absorpt_correction_T_max  0.91377
_exptl_absorpt_correction_T_min  0.80736
_exptl_absorpt_correction_type   empirical
_exptl_crystal_density_diffrn    1.637
_exptl_crystal_F_000             512
_exptl_crystal_size_max          0.30
_exptl_crystal_size_mid          0.10
_exptl_crystal_size_min          0.10
_refine_diff_density_max         0.485
_refine_diff_density_min         -0.383
_refine_diff_density_rms         0.072
_refine_ls_extinction_coef       0.0018(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   1.124
_refine_ls_goodness_of_fit_obs   1.152
_refine_ls_matrix_type           full
_refine_ls_number_parameters     166
_refine_ls_number_reflns         2031
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.164
_refine_ls_restrained_S_obs      1.152
_refine_ls_R_factor_all          0.0342
_refine_ls_R_factor_obs          0.0251
_refine_ls_shift/esd_max         -0.002
_refine_ls_shift/esd_mean        0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'w=1/[\s^2^(Fo^2^)+(0.0092P)^2^+1.1138P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_all         0.0541
_refine_ls_wR_factor_obs         0.0491
_reflns_number_observed          1823
_reflns_number_total             2138
_reflns_observed_criterion       >2sigma(I)
_cod_data_source_file            b110998g.txt
_cod_data_source_block           compound19
_cod_depositor_comments
;
The following automatic conversions were performed:

'_refine_ls_weighting_scheme' value 'calc
w=1/[\s^2^(Fo^2^)+(0.0092P)^2^+1.1138P] where P=(Fo^2^+2Fc^2^)/3' was
changed to 'calc'. New tag '_refine_ls_weighting_details' was
created. The value of the new tag was set to
'w=1/[\s^2^(Fo^2^)+(0.0092P)^2^+1.1138P] where P=(Fo^2^+2Fc^2^)/3'.

Automatic conversion script
Id: cif_fix_values 3143 2015-03-26 13:38:13Z robertas 
;
_cod_original_cell_volume        1031.0(5)
_cod_original_sg_symbol_H-M      P2(1)/c
_cod_database_code               7011352