Near-IR absorption of chloranil–alkylbenzene triplet exciplexes: estimation of the transfer integral between the triplet excited state (DA*) and the ion-pair state (D+A−)

Triplet exciplexes between chloranil and alkylbenzenes (benzene, toluene, m-xylene and mesitylene) have been studied by near-IR transient absorption spectroscopy. In the near-IR wavelength range (600–1600 nm), the charge transfer transition from a triplet excited state to an ion-pair state of these exciplexes can be observed. From the peak positions, the transfer integral V between the triplet excited state and the ion-pair state can be estimated as about V=0.5 eV.