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_4111318
_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_sum            'C29 H26 N2 O2'
_chemical_formula_weight         434.52
_space_group_IT_number           19
_symmetry_cell_setting           orthorhombic
_symmetry_space_group_name_Hall  'P 2ac 2ab'
_symmetry_space_group_name_H-M   'P 21 21 21'
_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            4
_cell_length_a                   11.9830(10)
_cell_length_b                   13.063(2)
_cell_length_c                   14.646(2)
_cell_measurement_reflns_used    2167
_cell_measurement_temperature    153(2)
_cell_measurement_theta_max      27.5
_cell_measurement_theta_min      1
_cell_volume                     2292.6(5)
_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      153(2)
_diffrn_measured_fraction_theta_full 0.842
_diffrn_measured_fraction_theta_max 0.842
_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  0.0699
_diffrn_reflns_av_sigmaI/netI    0.0967
_diffrn_reflns_limit_h_max       13
_diffrn_reflns_limit_h_min       -13
_diffrn_reflns_limit_k_max       15
_diffrn_reflns_limit_k_min       -15
_diffrn_reflns_limit_l_max       17
_diffrn_reflns_limit_l_min       -17
_diffrn_reflns_number            2839
_diffrn_reflns_theta_full        24.99
_diffrn_reflns_theta_max         24.99
_diffrn_reflns_theta_min         2.09
_exptl_absorpt_coefficient_mu    0.079
_exptl_absorpt_correction_type   none
_exptl_crystal_colour            yellow
_exptl_crystal_density_diffrn    1.259
_exptl_crystal_description       prisms
_exptl_crystal_F_000             920
_exptl_crystal_size_max          0.23
_exptl_crystal_size_mid          0.15
_exptl_crystal_size_min          0.11
_refine_diff_density_max         0.166
_refine_diff_density_min         -0.186
_refine_diff_density_rms         0.038
_refine_ls_abs_structure_details 'Flack H D (1983), Acta Cryst. A39, 876-881'
_refine_ls_extinction_coef       0.0064(19)
_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   1.041
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     305
_refine_ls_number_reflns         1945
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.041
_refine_ls_R_factor_all          0.1258
_refine_ls_R_factor_gt           0.0632
_refine_ls_shift/su_max          0.029
_refine_ls_shift/su_mean         0.002
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0417P)^2^+1.3047P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1264
_refine_ls_wR_factor_ref         0.1541
_reflns_number_gt                1181
_reflns_number_total             1945
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            ja067475wsi20061023_034039_2.cif
_cod_data_source_block           mds233
_cod_original_cell_volume        2292.5(5)
_cod_database_code               4111318