OPTICAL AND ELECTROCHEMICAL PROPERTIES OF CIS-1,2-DICYANO-1,2-BIS (2,4,5-TRIMETHYL-3-THIENYL)ETHENE

Optical and electrochemical properties of cis-1,2-dicyano-1,2-bis(2,4,5-trimethyl-3-thienyl)ethene (CMTE) have been studied by absorption spectroscopy, cyclic voltammetry, fast sweep voltammetry, and in-situ electrochemical absorptiometry. HOMO and LUMO levels of the CMTE are evaluated from absorption spectra and voltammetry. The lifetimes of unstable cation radicals formed by the electrochemical oxidation of CMTE in closed and open forms are evaluated by the fast sweep voltammetry. Electrochemical isomerization of closed form CMTE is studied by in-situ electrochemical absorptiometry, and the current efficiency is observed to be higher than 600%. The isomerization mechanism and kinetics have been studied taking chain electron transfer reaction between the cation radical of the open form CMTE and the neutral closed farm CMTE into consideration.