EPR study on the complex formed by charge-transfer process between ground-state acceptor 2, 3-dicyano-5, 6-dichloro-1,4-benzoquinone and some donors and on cation radical of perylene (or pyrene)

EPR study showed that the semi-quinone radical anion of 2,3-dicyano-5,6-dic hloro-1,4-benzoquinone (DDQ) was formed in a charge transfer process betwee n ground-state DDQ as acceptor and each one of following ground state donor s, i.e., 4- methyl-4'-tridecyl-2, 2'-bipyridyl; 4-methyl-4'-nonyl-2,2'-bipy ridyl; bis(2,2'-bipyridyl) (4-methyl-4'-heptadecyl-2,2'-bipyridyl)ruthenium (2+) perchlorate and perylene, EPR study also showed that there are perylen e cation radical and pyrene cation radical in the following experimental co nditions: (a) in 98% sulfuric acid, (b) 10(-3) mol/L perylene (or pyrene) w as dissolved in trifluoroacetic acid-nitrobenzene (1: 1 V/ V).