Optical T-T absorption of salicylidene-p-toluidine in solution

The observation of triplet-triplet absorption of salicylidene-p-toluidine, is complicated by the possible colored isomer formation during the optical pumping. The short-lived (singlet-singlet) and long-lived (triplet-triplet) absorption spectra were recorded phographically by microsecond flash and nanosecond laser flash photolysis techniques. Salicylidene-aniline complexes were purified by repeated recrystallisation until further recrystallisation produced no further changes for X-ray diffraction pattern and optical absorption, emission properties.