Mapping the Complete Reaction Path of a Complex Photochemical Reaction.

摘要: We probe the dynamics of dissociating CS_{2} molecules across entire reaction pathway upon excitation. Photoelectron spectroscopy measurements using laboratory-generated femtosecond extreme ultraviolet pulses monitor competing dissociation, internal conversion, and intersystem crossing dynamics. Dissociation occurs either in initially excited singlet manifold or, via crossing, triplet manifold. Both product channels are monitored show that, despite being more rapid, dissociation is minor that state products dominate final yield. explain this by a consideration accurate potential energy curves for both states. propose rapid conversion stabilizes population dynamically, allowing singlet-triplet relaxation efficient formation spin-forbidden on longer timescales. The study demonstrates importance measuring full defining mechanisms.