Triplet state photoexcitations in frozen solutions of oligothiophenes

Abstract We present studies of near-steady-state photoinduced absorption (PIA) spectroscopy of well-defined α-oligothiophenes (Tn, n = 6,7,9, and 11) in frozen 2MeTHF solution. The PIA spectra and the excited state lifetimes are consistent with the signatures of a photoexcited triplet state. The triplet photoexcitation is created via an intrachain mechanism and decays nonradiatively with monomolecular kinetics.