Charge-transfer interactions in the intramolecular quenching of carbonyl triplets by β-aryl substituents

Abstract

The triplet decay rates of ten β-aryl-4-methoxypropiophenone derivatives in methanol, acetonitrile, toluene and isooctane solution at 21 °C correlate with δ⁺ substituent constants (p⁺–1.8 ± 0.2), indicating that charge-transfer exciplex interactions between the aryl group (donor) and the carbonyl group (acceptor) play a dominant role in the intramolecular β-aryl quenching of carbonyl n,πtriplets.