Single-Route Reaction Mechanisms

Graph-theoretical methods for describing complex chemical reactions are reviewed and directed bipartite graphs are found to be the most convenient ones. Subgraphs of reaction intermediates are advocated as a tool for identifying and classifying reaction mechanisms. The notion of reaction intermediate is revisited, and the special class of dualistic intermediates is defined. The topological analysis of the single-route mechanisms resulted in identifying three classes of these mechanisms: catalytic, noncatalytic, and mixed, the latter including among others autocatalytic and autoinhibition reactions. The graph-theoretical basis is thus provided for the mechanistic classification of complex multiroute reactions.