This is the first book to concentrate on elucidating chemical reactivity from the viewpoint of molecular topology. Describing the most fundamental structural patterns in molecules, topology and graph theory are regarded to be the ideal tools for exploring the relationships between the structure and the properties of chemical compounds. A team of internationally recognized experts from seven countries present a variety of graph-theoretical and topological approaches to chemical reactivity. The specific topics covered include among others, the latest developments in the interplay between graph theory and molecular orbital theory, three dimensional molecular shapes and their changes, isomerization reactions in organic and inorganic chemistry, topological indices and their application to structure-reactivity relationships and mechanistic studies. Useful topology-based reactivity rules and more general principles controlling topology changes in chemical reactions are also presented. For researchers, teachers and students in all areas of chemistry.