THE POLANYI LECTURE - THE COLORFUL WORLD OF COMPLEX-FORMING BIMOLECULAR REACTIONS

The author's Polanyi Lecture 1992 is summarized, discussing experimental examples of complex-forming bimolecular reactions, their identification by pressure and temperature dependence as well as isotope labelling studies, and their theoretical analysis. The still fragmentary theoretical treatment involves all ingredients of unimolecular rate theory, relying heavily on quantum-chemical characterizations of reaction pathways and of the corresponding entrance and exit transition states. The reactions are often governed by rotational as well as vibrational 'channel switching'. Ion-neutral molecule and neutral-neutral molecule reactions show analogous behaviour, although quantitative differences are observed.