Niobium complexes containing a new chiral heteroscorpionate ligand and the reactivity of such a complex with O2 to give the first gem-diolate niobium complex
Otero, A.; Fernández-Baeza, J.; Antiñolo, A.; Tejeda, J.; Lara-Sánchez, A.; Sánchez-Barba, L.; Expósito, M. T.; Rodríguez, A. M.; Dalton Transactions  (2003) 1614–; doi:10.1039/b300497j

data_7012718
_publ_section_title
;
 Niobium complexes containing a new chiral heteroscorpionate ligand and
 the reactivity of such a complex with O2 to give the first gem-diolate
 niobium complex
;
_journal_issue                   8
_journal_name_full               'Dalton Transactions'
_journal_page_first              1614
_journal_paper_doi               10.1039/b300497j
_journal_year                    2003
_chemical_formula_sum            'C43 H38 Cl4 N8 Nb2 O4'
_chemical_formula_weight         1058.44
_space_group_IT_number           167
_symmetry_cell_setting           trigonal
_symmetry_space_group_name_Hall  '-R 3 2"c'
_symmetry_space_group_name_H-M   'R -3 c :H'
_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                120.00
_cell_formula_units_Z            18
_cell_length_a                   36.442(5)
_cell_length_b                   36.442(8)
_cell_length_c                   19.618(3)
_cell_measurement_reflns_used    25
_cell_measurement_temperature    293(2)
_cell_volume                     22563(7)
_computing_cell_refinement       'Nonius (control program)'
_computing_data_collection       'Nonius (control program)'
_computing_data_reduction        'XCAD4 (Harms, Wocadlo, 1995)'
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1990)'
_diffrn_ambient_temperature      293(2)
_diffrn_measured_fraction_theta_full 0.983
_diffrn_measured_fraction_theta_max 0.983
_diffrn_measurement_device_type  'four circle diffractometer Nonius-Mach3'
_diffrn_measurement_method       '\w/2\q 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  0.1485
_diffrn_reflns_av_sigmaI/netI    0.1305
_diffrn_reflns_limit_h_max       48
_diffrn_reflns_limit_h_min       0
_diffrn_reflns_limit_k_max       12
_diffrn_reflns_limit_k_min       -48
_diffrn_reflns_limit_l_max       25
_diffrn_reflns_limit_l_min       -24
_diffrn_reflns_number            17979
_diffrn_reflns_theta_full        27.99
_diffrn_reflns_theta_max         27.99
_diffrn_reflns_theta_min         2.24
_diffrn_standards_interval_time  60
_diffrn_standards_number         2
_exptl_absorpt_coefficient_mu    0.716
_exptl_absorpt_correction_type   none
_exptl_crystal_density_diffrn    1.402
_exptl_crystal_density_method    'not measured'
_exptl_crystal_F_000             9612
_exptl_crystal_size_max          0.4
_exptl_crystal_size_mid          0.3
_exptl_crystal_size_min          0.1
_refine_diff_density_max         0.294
_refine_diff_density_min         -0.359
_refine_diff_density_rms         0.062
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   0.831
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     265
_refine_ls_number_reflns         5954
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      0.831
_refine_ls_R_factor_all          0.3362
_refine_ls_R_factor_gt           0.0531
_refine_ls_shift/su_max          0.159
_refine_ls_shift/su_mean         0.022
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0452P)^2^+0.0000P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0912
_refine_ls_wR_factor_ref         0.1659
_reflns_number_gt                1184
_reflns_number_total             5954
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            b300497j.txt
_cod_data_source_block           7
_cod_original_sg_symbol_H-M      R-3c
_cod_database_code               7012718