BODIPY-Pyrene and Perylene Dyads as Heavy-Atom-Free Singlet Oxygen Sensitizers

Abstract

Dyads combining BODIPY as an electron acceptor and pyrene or perylene as electron donor subunits were prepared and their photophysical properties were studied by steady-state and transient spectroscopy. Depending on the structure of the subunits and the polarity of the media, the dyads show either bright fluorescence or photo-induced electron transfer (PeT) in solution. Charge-transfer (CT) states formed as a result of PeT and were found to yield triplet excited states of the BODIPY. In the presence of molecular oxygen, the dyads sensitize singlet oxygen (1O2) with quantum yields of up to 0.75.