Polynuclear tantalum oxoalkoxides. Crystal structures of [Ta8O10(OEt)20], [Ta7O9(OPri)17] and [Ta5O7(OBut)11]·C6H5Me
Isaac Abrahams; Donald C. Bradley; Halina Chudzynska; Majid Motevalli; Paul O'Shaughnessy; J. Chem. Soc., Dalton Trans.  (2000) 2685–2691; doi:10.1039/b001797n

data_7009542
_publ_section_title
;
 Polynuclear tantalum oxoalkoxides. Crystal structures of
 [Ta8O10(OEt)20], [Ta7O9(OPri)17] and [Ta5O7(OBut)11]&#x00B7;C6H5Me
;
_journal_issue                   16
_journal_name_full               'J. Chem. Soc., Dalton Trans.'
_journal_page_first              2685
_journal_page_last               2691
_journal_paper_doi               10.1039/b001797n
_journal_year                    2000
_chemical_compound_source        'synthesis as described'
_chemical_formula_moiety         'C40 H100 O30 Ta8'
_chemical_formula_structural     'C40 H100 O30 TA8'
_chemical_formula_sum            'C40 H100 O30 Ta8'
_chemical_formula_weight         2508.8
_space_group_IT_number           14
_symmetry_cell_setting           monoclinic
_symmetry_Int_Tables_number      14
_symmetry_space_group_name_Hall  '-P 2yn'
_symmetry_space_group_name_H-M   'P 1 21/n 1'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     Patterson
_atom_sites_solution_secondary   difmap
_audit_conform_dict_location
ftp://ftp.iucr.org/cifdics/cif_core_2.1beta5.dic
_audit_conform_dict_name         cif_core.dic
_audit_conform_dict_version      2.1beta5
_audit_creation_date             2000-02-29T20:08:26-00:00
_audit_creation_method           'WinGX routine CIF_UPDATE'
_cell_angle_alpha                90
_cell_angle_beta                 90.090(10)
_cell_angle_gamma                90
_cell_formula_units_Z            2
_cell_length_a                   16.956(2)
_cell_length_b                   14.1310(10)
_cell_length_c                   14.927(2)
_cell_measurement_reflns_used    25
_cell_measurement_temperature    293(2)
_cell_measurement_theta_max      14.42
_cell_measurement_theta_min      11.48
_cell_measurement_wavelength     0.71073
_cell_volume                     3576.6(7)
_computing_cell_refinement       'CAD4/PC (Enraf Nonius, 1994)'
_computing_data_collection       'CAD4/PC (Enraf Nonius, 1994)'
_computing_data_reduction        'XCAD4 (Harms & Wocadlo, 1995)'
_computing_molecular_graphics    'Ortep-3 for Windows (Farrugia, 1997)'
_computing_publication_material  'WinGX publication routines (Farrugia, 1999)'
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1997)'
_diffrn_ambient_temperature      293(2)
_diffrn_detector                 'scintillation LiI'
_diffrn_detector_dtime           1.195
_diffrn_measured_fraction_theta_full 0.977
_diffrn_measured_fraction_theta_max 0.977
_diffrn_measurement_device       '\k-geometry diffractometer'
_diffrn_measurement_device_type  'Enraf Nonius CAD4'
_diffrn_measurement_method       'non-profiled omega/2theta scans'
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_probe          x-ray
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0534
_diffrn_reflns_av_sigmaI/netI    0.0487
_diffrn_reflns_limit_h_max       20
_diffrn_reflns_limit_h_min       -20
_diffrn_reflns_limit_k_max       16
_diffrn_reflns_limit_k_min       0
_diffrn_reflns_limit_l_max       17
_diffrn_reflns_limit_l_min       0
_diffrn_reflns_number            6535
_diffrn_reflns_theta_full        25.16
_diffrn_reflns_theta_max         25.16
_diffrn_reflns_theta_min         1.82
_diffrn_source                   'Enraf Nonius FR590'
_diffrn_standards_decay_%        4
_diffrn_standards_interval_time  60
_diffrn_standards_number         2
_exptl_absorpt_coefficient_mu    12.252
_exptl_absorpt_correction_T_max  0.0468
_exptl_absorpt_correction_T_min  0.0052
_exptl_absorpt_correction_type   refdelf
_exptl_absorpt_process_details
;
        Walker, N. & Stuart, D (1983) Acta. Cryst. A39, 158-166
;
_exptl_crystal_colour            Colorless
_exptl_crystal_density_diffrn    2.33
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       prism
_exptl_crystal_F_000             2328
_exptl_crystal_size_max          0.4
_exptl_crystal_size_mid          0.3
_exptl_crystal_size_min          0.25
_refine_diff_density_max         1.453
_refine_diff_density_min         -2.269
_refine_diff_density_rms         0.321
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   0.982
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     355
_refine_ls_number_reflns         6277
_refine_ls_number_restraints     29
_refine_ls_restrained_S_all      0.983
_refine_ls_R_factor_all          0.115
_refine_ls_R_factor_gt           0.0688
_refine_ls_shift/su_max          0.083
_refine_ls_shift/su_mean         0.005
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.1468P)^2^+0.0000P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1799
_refine_ls_wR_factor_ref         0.2045
_reflns_number_gt                4001
_reflns_number_total             6277
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            b001797n.txt
_cod_data_source_block           h-ta2j
_cod_original_sg_symbol_H-M      'P 21/n'
_cod_database_code               7009542
_exptl_absorpt_factor_mur        3.063
_diffrn_standards_decay_corr_max 1.058
_diffrn_standards_decay_corr_min 0.961