Michael Thomas Clark

Dioxathiadiaza-heteropentalenes. New Photosystem-I electron acceptors

Abstract The redox properties of some dioxathiadiaza-heteropentalenes have been studied by pulse radiolysis and cyclic voltammetry. The midpoint potential at pH 7 for reduction of this class of compounds to the corresponding anion radical is comparable with the first reduction potential of the bipyridinium herbicides. The heteropentalenes act as Photosystem-I electron acceptors at concentrations of the order of 1 · 10 −6 M. The herbicidal properties of the heteropentalenes are similar to those of the bipyridinium herbicides.

The synthesis and electrochemical properties of some novel photosynthesis electron acceptors

Arange of dioxathiadiaza heteropentalenes have been prepared and their electrochemical properties have been studied by cyclic voltammetry and e.s.r. spectoscopy. It has been found that these compounds form stable anion radicals in the absence of oxygen and have half-peak reduction potentials in the same range as the bypyridinium compounds such as paraquat (mehyl viologen) or diquat.