Picosecond Relaxation Dynamics in Polydiacetylene-pTS

Time resolved absorption spectroscopy as well as transient grating measurements were performed on polydiacetylene-pTs. Singlet exciton lifetimes of 0.8 + 0.2 ps at 300K and 1.1 + 0.2 ps at 5K were measured. We propose that the observed nonradiative relaxation proceeds through a conformationally relaxed singlet state which lives for roughly 1.0 ps and 3.4 at 300K and 5K respectively. Data pertinent to the formation of triplet excitons is also presented and discussed.