Ping-Pong Electron Transfer through DNA

Herein we describe a novel Ir system that is able to promote the reduction of pyrimidine bases from a distance without the presence of an external quencher. Instead, DNA-mediated ET is triggered by DNA-mediated HT. Thus, photoactivation of these Ir assemblies results in both a forward and a reverse pattern for charge migration, which we term ping-pong electron transfer through DNA (Scheme 1).