Determination of N-Heterocyclic Carbene (NHC) Steric and Electronic Parameters using the [(NHC)Ir(CO)2Cl] System
Kelly III, Roy A.; Clavier, Hervé; Giudice, Simona; Scott, Natalie M.; Stevens, Edwin D.; Bordner, Jon; Samardjiev, Ivan; Hoff, Carl D.; Cavallo, Luigi; Nolan, Steven P.; Organometallics 27 (2008) 202–; doi:10.1021/om701001g

data_4070781
_publ_section_title
;
 Determination of N-Heterocyclic Carbene (NHC) Steric and Electronic
 Parameters using the [(NHC)Ir(CO)2Cl] System
;
_journal_issue                   2
_journal_name_full               Organometallics
_journal_page_first              202
_journal_paper_doi               10.1021/om701001g
_journal_volume                  27
_journal_year                    2008
_chemical_formula_sum            'C23 H26 Cl Ir N2 O2'
_chemical_formula_weight         590.11
_chemical_name_systematic
; 
 ? 
;
_space_group_IT_number           45
_symmetry_space_group_name_Hall  'I 2 -2c'
_symmetry_space_group_name_H-M   'I b a 2'
_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                90.00
_cell_formula_units_Z            8
_cell_length_a                   24.620(3)
_cell_length_b                   24.621(4)
_cell_length_c                   8.4498(11)
_cell_measurement_temperature    298(2)
_cell_volume                     5122.0(12)
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1990)'
_diffrn_ambient_temperature      298(2)
_diffrn_measured_fraction_theta_full 0.995
_diffrn_measured_fraction_theta_max 0.995
_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  0.1103
_diffrn_reflns_av_sigmaI/netI    0.0730
_diffrn_reflns_limit_h_max       23
_diffrn_reflns_limit_h_min       -23
_diffrn_reflns_limit_k_max       23
_diffrn_reflns_limit_k_min       -23
_diffrn_reflns_limit_l_max       8
_diffrn_reflns_limit_l_min       -8
_diffrn_reflns_number            11671
_diffrn_reflns_theta_full        20.00
_diffrn_reflns_theta_max         20.00
_diffrn_reflns_theta_min         2.62
_exptl_absorpt_coefficient_mu    5.336
_exptl_crystal_density_diffrn    1.530
_exptl_crystal_density_method    'not measured'
_exptl_crystal_F_000             2304
_refine_diff_density_max         0.837
_refine_diff_density_min         -0.352
_refine_diff_density_rms         0.100
_refine_ls_abs_structure_details 'Flack H D (1983), Acta Cryst. A39, 876-881'
_refine_ls_abs_structure_Flack   0.01(2)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   0.934
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     270
_refine_ls_number_reflns         2387
_refine_ls_number_restraints     241
_refine_ls_restrained_S_all      0.915
_refine_ls_R_factor_all          0.0546
_refine_ls_R_factor_gt           0.0345
_refine_ls_shift/su_max          2.655
_refine_ls_shift/su_mean         0.010
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0288P)^2^+0.0000P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0760
_refine_ls_wR_factor_ref         0.0794
_reflns_number_gt                1640
_reflns_number_total             2387
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            om701001g-file012.cif
_cod_data_source_block           c:\docume~1\owner\desktop\simesc~1\x471
_cod_database_code               4070781