Low-Valent Ditantalum Complex Ta2(μ-BH3)(μ-dmpm)3(η2-BH4)2: First Dinuclear Compound Containing a Bridging BH3 Group with Direct Ta-B Bonds
F. Albert Cotton; Carlos A. Murillo; Xiaoping Wang; Journal of the American Chemical Society 120 (1998) 9594–9599; doi:10.1021/ja9817242

data_4116838
_publ_section_title
;
 Low-Valent Ditantalum Complex Ta2(\m-BH3)(\m-dmpm)3(\h2-BH4)2: First
 Dinuclear Compound Containing a Bridging BH3 Group with Direct Ta-B Bonds
;
_journal_name_full               'Journal of the American Chemical Society'
_journal_page_first              9594
_journal_page_last               9599
_journal_paper_doi               10.1021/ja9817242
_journal_volume                  120
_journal_year                    1998
_chemical_compound_source        synthesis
_chemical_formula_moiety         (CH3)2P(BH3)CH2P(BH3)(CH3)2
_chemical_formula_sum            'C5 H20 B2 P2'
_chemical_formula_weight         163.77
_chemical_melting_point          425(2)
_space_group_IT_number           178
_symmetry_cell_setting           hexagonal
_symmetry_space_group_name_Hall  'P 61 2 (0 0 5)'
_symmetry_space_group_name_H-M   'P 61 2 2'
_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                120.00
_cell_formula_units_Z            6
_cell_length_a                   6.279(1)
_cell_length_b                   6.279(1)
_cell_length_c                   47.46(1)
_cell_measurement_reflns_used    25
_cell_measurement_temperature    123(2)
_cell_measurement_theta_max      19.0
_cell_measurement_theta_min      18.6
_cell_volume                     1620.5(5)
_computing_cell_refinement       'CAD4 V5'
_computing_data_collection       'CAD4 V5'
_computing_data_reduction        'XCAD4 (Harms, 1993)'
_computing_structure_refinement  'SHELXL-93 (Sheldrick, 1993)'
_computing_structure_solution    'SHELXS-86 (Sheldrick, 1990)'
_diffrn_ambient_temperature      123(2)
_diffrn_measurement_device       'Enraf Nonius CAD4'
_diffrn_measurement_method       'Omega-theta scans'
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'normal-focus sealed tube'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0532
_diffrn_reflns_av_sigmaI/netI    0.0488
_diffrn_refln_scan_mode_backgd   mo
_diffrn_refln_scan_width         0.70
_diffrn_reflns_limit_h_max       5
_diffrn_reflns_limit_h_min       -5
_diffrn_reflns_limit_k_max       5
_diffrn_reflns_limit_k_min       -6
_diffrn_reflns_limit_l_max       51
_diffrn_reflns_limit_l_min       -30
_diffrn_reflns_number            1842
_diffrn_reflns_theta_max         22.46
_diffrn_reflns_theta_min         2.57
_diffrn_standards_decay_%        0
_diffrn_standards_interval_time  60
_diffrn_standards_number         3
_exptl_absorpt_coefficient_mu    0.334
_exptl_absorpt_correction_T_max  0.982
_exptl_absorpt_correction_T_min  0.853
_exptl_absorpt_correction_type   psi-scan
_exptl_crystal_colour            colorless
_exptl_crystal_density_diffrn    1.007
_exptl_crystal_description       hexagon
_exptl_crystal_F_000             540
_exptl_crystal_size_max          0.28
_exptl_crystal_size_mid          0.26
_exptl_crystal_size_min          0.24
_refine_diff_density_max         0.237
_refine_diff_density_min         -0.139
_refine_diff_density_rms         0.038
_refine_ls_abs_structure_details 'Flack H D (1983), Acta Cryst. A39, 876-881'
_refine_ls_abs_structure_Flack   0.25(41)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_all   1.195
_refine_ls_goodness_of_fit_obs   1.231
_refine_ls_hydrogen_treatment    refall
_refine_ls_matrix_type           full
_refine_ls_number_parameters     82
_refine_ls_number_reflns         708
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.205
_refine_ls_restrained_S_obs      1.231
_refine_ls_R_factor_all          0.0476
_refine_ls_R_factor_obs          0.0333
_refine_ls_shift/esd_max         0.000
_refine_ls_shift/esd_mean        0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'w=1/[\s^2^(Fo^2^)+(0.0336P)^2^+0.5745P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_all         0.0833
_refine_ls_wR_factor_obs         0.0785
_reflns_number_observed          615
_reflns_number_total             709
_reflns_observed_criterion       >2sigma(I)
_cod_data_source_file            ja9817242_1.cif
_cod_data_source_block           (2)
_cod_depositor_comments
;
The following automatic conversions were performed:

'_diffrn_refln_scan_mode_backgd' value 'MO' changed to 'mo' according
to the built-in table from CIF Core dictionary named 'cif_core.dic'
version 2.4.1 from 2010-06-29.

'_exptl_absorpt_correction_type'
value 'psi scan' changed to 'psi-scan' according to the built-in
table from CIF Core 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^)+(0.0336P)^2^+0.5745P] 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^)+(0.0336P)^2^+0.5745P] where P=(Fo^2^+2Fc^2^)/3'.

Automatic conversion script
Id: cif_fix_values 3143 2015-03-26 13:38:13Z robertas 
;
_cod_database_code               4116838