Polish chemist who worked on molecular orbital theory with Robert Woodward and developed the Woodward–Hoffmann rules for the conservation of orbital symmetry (the arrangement of electrons around the nucleus; see orbital, atomic), which predict the conditions under which certain organic reactions can occur. He shared the Nobel Prize for Chemistry in 1981 with Kenichi Fukui for his theories concerning chemical reactions.
His findings were explained in his book Conservation of Orbital Symmetry (1969). From this work, chemists have a greater understanding of bonding and the prediction of chemicals synthesized by others, as well as the bonding of chemicals adsorbed on surfaces. Hoffmann also experimented in various branches of inorganic chemistry.
Hoffmann was born in the town of Złoczów, Poland (now Zolochev, in the Ukraine), during the start of the Nazi campaign in Poland. When he was four years old his family was detained in a labour camp under the occupation, and his father was fatally wounded by soldiers when he tried to break out. Remarkably, in 1943, Hoffmann escaped undetected and was concealed by friends in a school storeroom, emerging as a refugee when the war ended.
Hoffmann and his mother then travelled to the USA, reaching New York City in 1949. Hoffmann gained a place at Columbia University and finished his PhD in chemical physics in 1962. He was then elected a junior fellow at Harvard University. He continued his research at Cornell University from 1965, and took the post of John A Newman professor of physical science.
An articulate, affable man with a colourful personality, Hoffmann was keen to communicate the value of chemistry to the public, and to this end he wrote numerous articles in the press and presented a television series about the subject.