Book excerpt: A practical introduction to orbital interaction theory and its applications in modern organic chemistry Orbital interaction theory is a conceptual construct that lies at the very heart of modern organic chemistry. Comprising a comprehensive set of principles for explaining chemical reactivity, orbital interaction theory originates in a rigorous theory of electronic structure that also provides the basis for the powerful computational models and techniques with which chemists seek to describe and exploit the structures and thermodynamic and kinetic stabilities of molecules. Orbital Interaction Theory of Organic Chemistry, Second Edition introduces students to the fascinating world of organic chemistry at the mechanistic level with a thoroughly self-contained, well-integrated exposition of orbital interaction theory and its applications in modern organic chemistry. Professor Rauk reviews the concepts of symmetry and orbital theory, and explains reactivity in common functional groups and reactive intermediates in terms of orbital interaction theory. Aided by numerous examples and worked problems, he guides readers through basic chemistry concepts, such as acid and base strength, nucleophilicity, electrophilicity, and thermal stability (in terms of orbital interactions), and describes various computational models for describing those interactions. Updated and expanded, this latest edition of Orbital Interaction Theory of Organic Chemistry includes a completely new chapter on organometallics, increased coverage of density functional theory, many new application examples, and worked problems. The text is complemented by an interactive computer program that displays orbitals graphically and is available through a link to a Web site. Orbital Interaction Theory of Organic Chemistry, Second Edition is an excellent text for advanced-level undergraduate and graduate students in organic chemistry. It is also a valuable working resource for professional chemists seeking guidance on interpreting the quantitative data produced by modern computational chemists.