Abstract

Chemical reactions in condensed media can be thought of as consisting of four steps: 1) relative diffusion to the local reaction regime ("microenvironment"), 2) dynamics in the microenvironment ("microdynamics"), 3) electron and nuclear rearrangements, and 4) energy relaxation. Any or all of these steps may occur on picosecond timescales. The cis-trans isomerization problem omits step 1) and concentrates primarily on steps 2) and 3). Typical photochemical quenching reactions are primarily concerned with steps 1) and 2), while the I+I→I₂ recombination problem has mainly focussed on steps 3) and 4). Except for the latter type of problem, actual experimental examples of condensed phase chemical reactivity are fairly complex, and this complexity hides the very aspects of the problem that one would like to probe. Because of this, it is fair to say that almost nothing is known about the important steps 2) and 3) in the above scheme.

© 1984 Optical Society of America