Roald Hoffmann is a theoretical chemist who has straddled the traditional boundary between organic and inorganic chemistry. He has emphasized the role of aesthetics in science and the inherent beauty of chemical systems, and he values clarity and simplicity in the formulation of theories about chemistry. He is best known for constructing a method of predicting the course of chemical reactions that is based on the symmetry of electron orbitals . Called the Woodward-Hoffmann rules, he developed them in collaboration with Robert B. Woodward at Harvard, and these rules have enabled chemists to predict reactions without using complicated mathematical equations. The achievement has been widely recognized as the most important conceptual advance in organic chemistry since World War II, and for this Hoffmann shared the 1981 Nobel Prize in chemistry with Kenichi Fukui.

Hoffmann was born Roald Safran on July 18, 1937, in Zloczów, Poland on the eve of World...