Molecular Rearrangements of a Low-Valent Niobium Amide: Ligand C−H Bond Oxidative Addition and Reductive Elimination
Tayebani, Maryam; Feghali, Khalil; Gambarotta, Sandro; Yap, Glenn; Organometallics 17 (1998) 4282–; doi:10.1021/om980302y

data_4078403
_publ_section_title
;
 Molecular Rearrangements of a Low-Valent Niobium Amide:&#x00A0; Ligand
 C&#x2212;H Bond Oxidative Addition and Reductive Elimination
;
_journal_issue                   19
_journal_name_full               Organometallics
_journal_page_first              4282
_journal_paper_doi               10.1021/om980302y
_journal_volume                  17
_journal_year                    1998
_chemical_formula_sum            'C52 H50 N4 Nb2 O'
_chemical_formula_weight         932.78
_space_group_IT_number           19
_symmetry_cell_setting           orthorhombic
_symmetry_space_group_name_Hall  'P 2ac 2ab'
_symmetry_space_group_name_H-M   'P 21 21 21'
_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                 90.00
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   14.1827(7)
_cell_length_b                   15.5713(8)
_cell_length_c                   19.2238(9)
_cell_measurement_reflns_used    'reflections from 60 data frames'
_cell_measurement_temperature    183(2)
_cell_measurement_theta_max      28.29
_cell_measurement_theta_min      1.47
_cell_volume                     4245.4(4)
_computing_cell_refinement       'Siemens SAINT'
_computing_data_collection       'Siemens SMART'
_computing_data_reduction        'Siemens SHELXTL XPREP'
_computing_molecular_graphics    'Siemens SHELXTL XP'
_computing_publication_material  'Siemens SHELXTL XCIF'
_computing_structure_refinement  'SHELXL-93 (Sheldrick, 1993)'
_computing_structure_solution    'SHELXS-86 (Sheldrick, 1990)'
_diffrn_ambient_temperature      183(2)
_diffrn_measurement_device       'Siemens SMART CCD'
_diffrn_measurement_method       'hemisphere scans'
_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  0.0257
_diffrn_reflns_av_sigmaI/netI    0.0255
_diffrn_reflns_limit_h_max       18
_diffrn_reflns_limit_h_min       -18
_diffrn_reflns_limit_k_max       19
_diffrn_reflns_limit_k_min       -9
_diffrn_reflns_limit_l_max       26
_diffrn_reflns_limit_l_min       -24
_diffrn_reflns_number            26524
_diffrn_reflns_theta_max         28.80
_diffrn_reflns_theta_min         1.68
_diffrn_standards_decay_%        <1
_diffrn_standards_number         '50 standard frames at start and end'
_exptl_absorpt_coefficient_mu    0.584
_exptl_absorpt_correction_type   none
_exptl_crystal_colour            red
_exptl_crystal_density_diffrn    1.459
_exptl_crystal_description       block
_exptl_crystal_F_000             1920
_exptl_crystal_size_max          0.40
_exptl_crystal_size_mid          0.40
_exptl_crystal_size_min          0.40
_refine_diff_density_max         0.500
_refine_diff_density_min         -0.780
_refine_diff_density_rms         0.055
_refine_ls_abs_structure_details 'Flack H D (1983), Acta Cryst. A39, 876-881'
_refine_ls_abs_structure_Flack   -0.03(2)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_all   1.008
_refine_ls_goodness_of_fit_obs   1.001
_refine_ls_hydrogen_treatment    idealized
_refine_ls_matrix_type           full
_refine_ls_number_parameters     532
_refine_ls_number_reflns         9936
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.008
_refine_ls_restrained_S_obs      1.001
_refine_ls_R_factor_all          0.0219
_refine_ls_R_factor_obs          0.0211
_refine_ls_shift/esd_max         -0.056
_refine_ls_shift/esd_mean        0.003
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'w=1/[\s^2^(Fo^2^)+(0.0329P)^2^+1.5965P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_all         0.0572
_refine_ls_wR_factor_obs         0.0560
_reflns_number_observed          9741
_reflns_number_total             9936
_reflns_observed_criterion       >2sigma(I)
_cod_data_source_file            om980302y.cif
_cod_data_source_block           sg039
_cod_depositor_comments
;
The following automatic conversions were performed:

'_symmetry_cell_setting' value 'Orthorhombic' changed to
'orthorhombic' according to
/home/saulius/struct/CIF-dictionaries/cif_core.dic dictionary named
'cif_core.dic' version 2.4.1 from 2010-06-29.

Automatic conversion script
Id: cif_fix_values 1715 2011-07-08 13:25:40Z adriana 

The following automatic conversions were performed:

'_refine_ls_weighting_scheme' value 'calc
w=1/[\s^2^(Fo^2^)+(0.0329P)^2^+1.5965P] 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^)+(0.0329P)^2^+1.5965P] where P=(Fo^2^+2Fc^2^)/3'.

Automatic conversion script
Id: cif_fix_values 3143 2015-03-26 13:38:13Z robertas 
;
_cod_original_sg_symbol_H-M      P2(1)2(1)2(1)
_cod_database_code               4078403