Abstract

The mechanism of photodissociation of disulfide molecules and tire relaxation processes in the thiyl radicals formed have been studied with picosecond laser spectroscopy. Upon excitation of aromatic symmetrical disulfides R-Ph-S-S- Ph-K, where R = -H, -NH₂, or -N(C₂H₅); by Nd glass passively mode-locked laser pulses (λ_exc= 264 or 352 nn, τ_p = 6 ps), the phenylthiyl (1), p-aminophenylthiyl (II), and p-diethylaminophenylthiyl (III) radical absorption spectra are registered. The dissociative-state lifetime of disulfides is no longer than 10⁻¹ s. Quantum-chemical analysis of experimental data shows that the mechanism of disulfide photodissociation is predissociation.

© 1991 Optical Society of America