Type 2 photoelimination reaction of esters of aromatic carboxylic acids

Abstract

Aromatic esters of the type Ar·CO₂·CH₂·CHR¹R² are found to undergo a photoelimination reaction from both singlet and triplet excited states, though the process is inefficient from states of either multiplicity. Rate constants for the primary steps are evaluated for the systems p-MeO·C₆H₄·CO₂·CH₂·CHR¹R²(R¹= Me; R²= H, Me). Absorption and emission data suggest that the lowest singlet and triplet states in all the esters studied are ππ* in nature.