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 X 1O'O M-'sl. Upon quenching, a new intermediate is formed with a A, of 480 nm which is characteristic of the charge-transfer species. The rate of the decay of the transient species ...
