spectra were recorded
using a Shimadzu UV3100PC at room temperature. The XPS measurements
were carried out on a Quantera-SXM spectrometer at room temperature.
Binding energies were measured relative to the C 1s peak (284.8 eV)
of an internal hydrocarbon. The diffuse reflectance spectra were recorded
on a Hitachi U-4000 spectrophotometer over the range from 200 to 2500
nm at room temperature. The infrared spectra were recorded on a PerkinElmer
Spectrum 400 over the range from 400 to 4000 cm–1 at room temperature. Cyclic voltammetric measurements were conducted
at room temperature using a BAS CV-50W or BAS 617E electrochemical
analyzer. Cyclic voltammograms were recorded with CH3CN
or CH2Cl2 solutions containing 0.1 M Bu4NPF6 as the supporting electrolyte. Conventional
three-electrode arrangement consisting of glassy carbon or Pt working
electrode, Ag/Ag+ reference electrode, and Pt wire counter
electrode was used. EPR spectra were measured on a JEOL TE-200 spectrometer. 1H NMR were conducted on a JEOL ECA-600.