1,4-Bis(trimethylsilyl)-1,4-diaza-2,5-cyclohexadienes as Strong Salt-Free Reductants for Generating Low-Valent Early Transition Metals with Electron-Donating Ligands.
Saito, Teruhiko; Nishiyama, Haruka; Tanahashi, Hiromasa; Kawakita, Kento; Tsurugi, Hayato; Mashima, Kazushi; Journal of the American Chemical Society 136 (2014) 5161–5170; doi:10.1021/ja501313s

data_4121617
_publ_section_title
;
 1,4-Bis(trimethylsilyl)-1,4-diaza-2,5-cyclohexadienes as Strong Salt-Free
 Reductants for Generating Low-Valent Early Transition Metals with
 Electron-Donating Ligands.
;
_journal_issue                   13
_journal_name_full               'Journal of the American Chemical Society'
_journal_page_first              5161
_journal_page_last               5170
_journal_paper_doi               10.1021/ja501313s
_journal_volume                  136
_journal_year                    2014
_chemical_formula_moiety         'C20 H30 Cl6 Ta2'
_chemical_formula_sum            'C20 H30 Cl6 Ta2'
_chemical_formula_weight         845.04
_chemical_melting_point          240(2)
_chemical_name_common            16
_chemical_name_systematic
; 
 ? 
;
_space_group_IT_number           15
_symmetry_cell_setting           monoclinic
_symmetry_space_group_name_Hall  '-C 2yc'
_symmetry_space_group_name_H-M   'C 1 2/c 1'
_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                 99.650(6)
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   14.731(2)
_cell_length_b                   8.3117(9)
_cell_length_c                   21.044(3)
_cell_measurement_reflns_used    2875
_cell_measurement_temperature    113(2)
_cell_measurement_theta_max      27.47
_cell_measurement_theta_min      3.07
_cell_volume                     2540.2(6)
_computing_cell_refinement       CrystalClear
_computing_data_collection       'CrystalClear (Rigaku, 2007)'
_computing_data_reduction        CrystalClear
_computing_molecular_graphics    'CrystalStructure 4.0 (Rigaku, 2010)'
_computing_publication_material  'CrystalStructure 4.0'
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1990)'
_diffrn_ambient_temperature      113(2)
_diffrn_detector_area_resol_mean 7.314
_diffrn_measured_fraction_theta_full 0.994
_diffrn_measured_fraction_theta_max 0.994
_diffrn_measurement_device_type  'Rigaku Mercury70'
_diffrn_measurement_method       \w
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'fine-focus sealed tube'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71075
_diffrn_reflns_av_R_equivalents  0.0601
_diffrn_reflns_av_sigmaI/netI    0.0653
_diffrn_reflns_limit_h_max       19
_diffrn_reflns_limit_h_min       -18
_diffrn_reflns_limit_k_max       10
_diffrn_reflns_limit_k_min       -10
_diffrn_reflns_limit_l_max       27
_diffrn_reflns_limit_l_min       -27
_diffrn_reflns_number            11447
_diffrn_reflns_theta_full        27.46
_diffrn_reflns_theta_max         27.46
_diffrn_reflns_theta_min         3.14
_diffrn_standards_number         0
_exptl_absorpt_coefficient_mu    9.246
_exptl_absorpt_correction_T_max  0.5250
_exptl_absorpt_correction_T_min  0.2869
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   'REQAB (Rigaku, 1998)'
_exptl_crystal_colour            green
_exptl_crystal_density_diffrn    2.210
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       block
_exptl_crystal_F_000             1592
_exptl_crystal_size_max          0.18
_exptl_crystal_size_mid          0.16
_exptl_crystal_size_min          0.08
_refine_diff_density_max         3.510
_refine_diff_density_min         -2.560
_refine_diff_density_rms         0.371
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.205
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     122
_refine_ls_number_reflns         2890
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.205
_refine_ls_R_factor_all          0.0845
_refine_ls_R_factor_gt           0.0791
_refine_ls_shift/su_max          0.000
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0000P)^2^+342.5060P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1756
_refine_ls_wR_factor_ref         0.1786
_reflns_number_gt                2644
_reflns_number_total             2890
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            ja501313s_si_003.cif
_cod_data_source_block           15
_cod_depositor_comments
;
The following automatic conversions were performed:

'_chemical_melting_point' value '238-242' was changed to '240(2)' -
the average value was taken and precision was estimated.

Automatic conversion script
Id: cif_fix_values 2281 2013-09-26 08:29:07Z andrius 
;
_cod_original_cell_volume        2540.1(6)
_cod_database_code               4121617