Abstract
Cyclic voltammetry (CV) for 2, 7-disubstituted phenazines (1mM, MeO (1), EtO (2), H (3), Cl (4), Br (5), COOEt (6)) was carried out in acetonitrile containing trifluoroacetic acid (TFA, 1% and 2%) and NaClO4 (0.1M) as a supporting electrolyte under N2 gas. Phenazines showed two cathodic peaks (Epc1 and Epc2) and these peaks had counterparts (Epa1 and Epa2, respectively). Plots of the peak potentials against σp were linear. The first cathodic wave corresponds to the reduction of singly protonated phenazines followed by proton transfer. The second cathodic wave corresponds to the reduction of the cation radical of dihydrophenazines to produce dihydrophenazine as a final product.ESR spectrometry of 1-6 in acetonitrile and in acetonitrile containing 1% TFA was conducted and computer simulation of the spectra was carried out. Splitting due to halogen or o-alkyl substituents was observed. Molecular orbital (MO) calculation of anion radicals generated from 1-6 and cation radicals generated from doubly protonated 1-6 did not give good agreement with the results of ESR spectrometry.
