Photo-induced Electron Transfer of Triphenylamine-Naphthaldiimide Dyads with Twisted Oligophenylene Spacers

Abstract

Recently, we have shown that simple triphenylamine-naphthaldiimide dyads using highly twisted (diphenylethynyl)benzene spacers give long-lived charge separated states of microsecond order with high efficiencies. For understanding the photophysical properties of these dyads, we have designed and synthesized similar triphenylamine-naphthaldiimide dyads linked with non-twisted or twisted oligophenylene as spacers whose lengthes are shorter than those of diphenylethynyl)benzene. In the twisted dyad system, it was found that triplet charge separated state was generated via the intersystem crossing within the radical ion pair.