Electrochemical properties of pyrazinothiadiazoles

Abstract

The reduction properties of some pyrazinothiadizoles have been measured by cyclic voltammetry and pulse radiolysis. Variation in substitution on the pyrazine ring has given compounds with half-peak reduction potentials varying between –280 and –1 100 mV (versus Ag–AgCl) in 3 : 1 methanol–water. Some of these compounds act as Photosystem I electron acceptors at a concentration lower than 10^–6 mol dm^–3. MNDO calculations have been used to help in the understanding of the redox processes involving this class of molecules.