Picosecond Dynamics of trans-Stilbene Photodimerization

Article abstract of DOI:10.1021/j100123a006

Picosecond absorption spectroscopy is used to examine the dynamics of the 2+2 photodimerization reaction of trans-stilbene in benzene.The quenching of the first excited singlet state of trans-stilbene by ground-state trans-stilbene occurs at the diffusion limit, 2.03 * 10¹⁰ M^-1 s^-1.Upon quenching, a new intermediate is formed with a λ_max of 480 nm which is characteristic of the charge-transfer species.The rate of the decay of the transient species is (2.40 +/- 0.37) * 10⁹ s^-1.The assignment of the transient to the excimer or a biradicaloid species at the pericyclic minimum is discussed.