Utilization of Transition-Metal Properties To Control Polyborane Formation. Synthesis of the arachno-Diiridahexaborane(12) 2,5-{Cp*IrH}2B4H8 and Its Conversion to the nido-Diiridahexaborane(10) 1,2-{Cp*Ir}2(-H)B4H7 (Cp* =5-C5Me5)
Xinjian Lei; Maoyu Shang; Thomas P. Fehlner; Organometallics 19 (2000) 118–120; doi:10.1021/om990816c

data_4063212
_publ_section_title
;
 Utilization of Transition-Metal Properties To Control Polyborane
 Formation. Synthesis of the arachno-Diiridahexaborane(12)
 2,5-{Cp*IrH}2B4H8 and Its Conversion to the nido-Diiridahexaborane(10)
 1,2-{Cp*Ir}2(-H)B4H7 (Cp* \\db 5-C5Me5)
;
_journal_name_full               Organometallics
_journal_page_first              118
_journal_page_last               120
_journal_paper_doi               10.1021/om990816c
_journal_volume                  19
_journal_year                    2000
_chemical_formula_sum            'C20 H38 B4 Ir2'
_chemical_formula_weight         706.14
_chemical_name_systematic
;

{(C5Me5)Ir}2B4H8

;
_space_group_IT_number           14
_symmetry_cell_setting           monoclinic
_symmetry_space_group_name_Hall  '-P 2yn'
_symmetry_space_group_name_H-M   'P 1 21/n 1'
_atom_sites_solution_hydrogens
;

idealized with riding models for C5Me5 groups and other hydrogen atoms were

located form Difference Fourier map and refined with bond lengthen constraint

;
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_audit_creation_method           SHELXL-97
_cell_angle_alpha                90.00
_cell_angle_beta                 93.448(15)
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   8.3011(14)
_cell_length_b                   19.742(3)
_cell_length_c                   14.552(3)
_cell_measurement_reflns_used    25
_cell_measurement_temperature    293(2)
_cell_measurement_theta_max      32
_cell_measurement_theta_min      30
_cell_volume                     2380.5(7)
_computing_cell_refinement       'CAD4-ARGUS (Enraf-Nonius, 1994)'
_computing_data_collection       'CAD4-ARGUS (Enraf-Nonius, 1994)'
_computing_data_reduction
;

chi90s (Boyle, 1997), xcad4 (Harms, 1997)

;
_computing_molecular_graphics    'ORTEP-III for Windows (Farrugia,1997)'
_computing_publication_material  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1990)'
_diffrn_ambient_temperature      293(2)
_diffrn_measured_fraction_theta_full 0.997
_diffrn_measured_fraction_theta_max 0.997
_diffrn_measurement_device_type  'Enraf-Nonius CAD4'
_diffrn_measurement_method       \w/2\q
_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  0.0330
_diffrn_reflns_av_sigmaI/netI    0.0417
_diffrn_reflns_limit_h_max       9
_diffrn_reflns_limit_h_min       -9
_diffrn_reflns_limit_k_max       23
_diffrn_reflns_limit_k_min       0
_diffrn_reflns_limit_l_max       17
_diffrn_reflns_limit_l_min       0
_diffrn_reflns_number            4345
_diffrn_reflns_theta_full        24.98
_diffrn_reflns_theta_max         24.98
_diffrn_reflns_theta_min         2.06
_diffrn_standards_decay_%        '0.9051 - 1.0186'
_diffrn_standards_interval_count 200
_diffrn_standards_interval_time  120
_diffrn_standards_number         3
_exptl_absorpt_coefficient_mu    11.171
_exptl_absorpt_correction_T_max  0.9966
_exptl_absorpt_correction_T_min  0.8515
_exptl_absorpt_correction_type   empirical
_exptl_crystal_colour            yellow
_exptl_crystal_density_diffrn    1.970
_exptl_crystal_density_meas      ?
_exptl_crystal_density_method    .
_exptl_crystal_description       plate
_exptl_crystal_F_000             1328
_exptl_crystal_size_max          0.38
_exptl_crystal_size_mid          0.12
_exptl_crystal_size_min          0.06
_refine_diff_density_max         2.072
_refine_diff_density_min         -1.284
_refine_diff_density_rms         0.172
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.118
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     259
_refine_ls_number_reflns         4177
_refine_ls_number_restraints     12
_refine_ls_restrained_S_all      1.116
_refine_ls_R_factor_all          0.0551
_refine_ls_R_factor_gt           0.0382
_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^)+(0.0452P)^2^+6.7817P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0942
_refine_ls_wR_factor_ref         0.1007
_reflns_number_gt                3339
_reflns_number_total             4177
_reflns_threshold_expression     >2sigma(I)
_cod_original_sg_symbol_H-M      P2(1)/n
_cod_database_code               4063212