Interaction of Duroquinone Lowest Triplet with Amines

Abstract

The reaction of the lowest triplet of duroquinone, 3Q, with tertiary amines (triethylamine TEA, diethylaniline DEA, triphenylamine TPA) has been investigated by laser flash absorption spectroscopy in non-polar (cyclohexane or benzene) and polar (acetonitrile) solvents. Three pathways of 3Q deactivation involving an exciplex as intermediate were observed: (i) an electron transfer to 3Q from TPA and DEA in a polar solvent, (ii) a H atom transfer to 3Q from DEA in a non-polar solvent and from TEA in a non-polar or a polar solvent, (iii) a physical quenching of 3Q by TPA in a non-polar solvent with no photoreduction products.