THE EFFECT OF 9‐ETHYLADENINE ON THE PHOTODIMERIZATION OF 1‐CYCLOHEXYLTHYMINE

Abstract— The photodimerization of 1‐cyclohexylthymine (l‐CT).and the effect of adding 9‐ethyladenine (9‐EA) on this reaction were studied in chloroform and/or acetonitrile solutions. The photodimerization of 1‐CT is shown to occur through an excited triplet state. 9‐EA works as an inhibitor against this reaction by quenching the excited singlet state of 1‐CT. It is suggested that a singlet exciplex made up from the excited state 1‐CT and the ground state 9‐EA by hydrogen‐bonding may play an important role in the quenching process.