Electrochemistry and Electrogenerated Chemiluminescence of a Novel Donor−Acceptor FPhSPFN Red Fluorophore

Abstract

We report here the electrogenerated chemiluminescence (ECL) of a red fluorophore diphenylaminospirobifluorenylfumaronitrile (FPhSPFN). FPhSPFN contains two diphenylamino groups as strong electron donors at the ends linked through a nonplanar bulky spirobifluorene linker to a common fumaronitrile group as a strong electron acceptor. The cyclic voltammetry of this compound shows two one-electron transfer reduction waves and one single overall two-electron oxidation wave consisting of closely spaced waves with a peak separation of 63 mV. Chronoamperometry with an ultramicroelectrode (UME) confirmed that each reduction wave involves a 1e transfer and that the oxidation wave contains an overall 2e transfer. The first reduction wave is Nernstian, Eo1,red = −1.09 V versus SCE, and the second reduction wave, Eo2,red = −1.50 V versus SCE, produces a film on the electrode. By comparison to a digital simulation, the oxidation is assigned to two reversible, closely spaced, one-electron processes for oxidation with Eo...