Quinone-Annulated N-Heterocyclic Carbene-Transition-Metal Complexes: Observation of π-Backbonding Using FT-IR Spectroscopy and Cyclic Voltammetry
Matthew D. Sanderson; Justin W. Kamplain; Christopher W. Bielawski; Journal of the American Chemical Society 128 (2006) 16514–16515; doi:10.1021/ja067475w

data_4111320
_publ_section_title
;
 Quinone-Annulated N-Heterocyclic Carbene-Transition-Metal Complexes:
 Observation of \p-Backbonding Using FT-IR Spectroscopy and Cyclic
 Voltammetry
;
_journal_name_full               'Journal of the American Chemical Society'
_journal_page_first              16514
_journal_page_last               16515
_journal_paper_doi               10.1021/ja067475w
_journal_volume                  128
_journal_year                    2006
_chemical_formula_moiety         ' C29 H26 N2 O2, Ag 1+, Cl 1-, 1/2 C4 H8 O'
_chemical_formula_sum            'C31 H30 Ag Cl N2 O2.5'
_chemical_formula_weight         613.89
_chemical_name_systematic
;
 ?
;
_space_group_IT_number           121
_symmetry_cell_setting           tetragonal
_symmetry_space_group_name_Hall  'I -4 2'
_symmetry_space_group_name_H-M   'I -4 2 m'
_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                   19.1960(7)
_cell_length_b                   19.1960(7)
_cell_length_c                   15.0434(5)
_cell_measurement_temperature    233(2)
_cell_volume                     5543.3(3)
_computing_cell_refinement       'Collect software, Nonius B.V. 1998'
_computing_data_collection       'Collect software, Nonius B.V. 1998'
_computing_data_reduction
;
DENZO and Scalepack (Otwinoski and Minor, 1997)
;
_computing_molecular_graphics    'XP SHELXTL/PC, Siemens Analytical'
_computing_structure_refinement  'XL SHELXTL/PC, Siemens Analytical'
_computing_structure_solution
;

SIR97 - Altomare A., Burla M.C., Camalli M., Cascarano G.L., Giacovazzo C., 
Guagliardi A., Moliterni A.G.G., Polidori G.,Spagna R.
;
_diffrn_ambient_temperature      233(2)
_diffrn_measured_fraction_theta_full 0.997
_diffrn_measured_fraction_theta_max 0.997
_diffrn_measurement_device_type  'Nonius Kappa CCD'
_diffrn_measurement_method       \w-scans
_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  0.0259
_diffrn_reflns_av_sigmaI/netI    0.0407
_diffrn_reflns_limit_h_max       24
_diffrn_reflns_limit_h_min       -24
_diffrn_reflns_limit_k_max       17
_diffrn_reflns_limit_k_min       -17
_diffrn_reflns_limit_l_max       19
_diffrn_reflns_limit_l_min       -19
_diffrn_reflns_number            6054
_diffrn_reflns_theta_full        27.50
_diffrn_reflns_theta_max         27.50
_diffrn_reflns_theta_min         3.00
_exptl_absorpt_coefficient_mu    0.856
_exptl_absorpt_correction_type   none
_exptl_crystal_colour            yellow
_exptl_crystal_density_diffrn    1.471
_exptl_crystal_description       plates
_exptl_crystal_F_000             2512
_exptl_crystal_size_max          0.16
_exptl_crystal_size_mid          0.16
_exptl_crystal_size_min          0.15
_refine_diff_density_max         0.424
_refine_diff_density_min         -0.348
_refine_diff_density_rms         0.055
_refine_ls_abs_structure_details 'Flack H D (1983), Acta Cryst. A39, 876-881'
_refine_ls_abs_structure_Flack   0.60(3)
_refine_ls_extinction_coef       0.00022(9)
_refine_ls_extinction_expression Fc^*^=kFc[1+0.001xFc^2^\l^3^/sin(2\q)]^-1/4^
_refine_ls_extinction_method     SHELXL
_refine_ls_goodness_of_fit_ref   1.081
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     168
_refine_ls_number_reflns         3315
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.081
_refine_ls_R_factor_all          0.0504
_refine_ls_R_factor_gt           0.0365
_refine_ls_shift/su_max          0.042
_refine_ls_shift/su_mean         0.004
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0254P)^2^+4.9515P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0699
_refine_ls_wR_factor_ref         0.0741
_reflns_number_gt                2738
_reflns_number_total             3315
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            ja067475wsi20061023_034039_5.cif
_cod_data_source_block           jknqag
_cod_original_formula_sum        'C31 H30 Ag Cl N2 O2.50'
_cod_database_code               4111320