The Chemistry Prize Committee has unanimously selected the following two candidates to equally share the 1988 Wolf Prize in Chemistry:
Joshua Jortner
Tel-Aviv University
Tel-Aviv, Israel
Raphael D. Levine
Hebrew University of Jerusalem
Jerusalem, Israel
for their incisive theoretical studies elucidating energy acquisition and disposal in molecular systems and mechanisms for dynamical selectivity and specificity.
Professor Joshua Jortner is one of the most influential theoretical physical chemists today. His works cover a vast range of fields, such as the theory of solvated electrons, properties of excited electronic states of molecules, coherent multiphoton processes, charge transfer in polar solvents and in biophysical systems, and the dynamics of supercooled large molecules and molecular clusters. His impact on each of these fields would have been enough to earn him worldwide recognition.
However, Jortnerīs most impressive achievement is undoubtedly his recognition and elucidation of the intramolecular nature of radiationless dissipation of energy in molecules of large and medium size. Based on a simple theoretical model (proposed in 1968 in collaboration with Mordechai Bixon), the basic notions specifying the energy acquisition process, the interstate coupling modes, and the mechanisms of energy disposal, were laid open.
Jortnerīs ideas and terminology became seminal to the study of laser chemistry, multiphoton processes in molecules, relaxation phenomena in condensed phases and the dynamics of biophysical systems, and had an indelible impact on the modern development of chemical physics and theoretical chemistry.
Professor Raphael D. Levine is one of the pioneers, and a leader of worldwide recognition, in the modern theory of chemically reactive collisions and unimolecular reactions. He has played a central role in the application of the principles of quantum mechanics to the description of physical change in a reaction from a microscopic point of view, introducing many new concepts and terms which became standard to this area. His pioneering works include the quantum theory of absolute rates, the first quantal treatment of molecular photodissociation, elucidation of the role of resonances in reactive molecular collisions, the theory of collision- induced dissociation, and (most recently) the foundations of dynamical stereochemistry.
Recognizing the insufficiency of the microscopic approach to fully comprehend the dynamics of too complex systems, Levine formulated a novel theoretical method for analysing the dynamical selectivity and specificity of molecular reactions, based on ideas borrowed from thermodynamics and information theory. His 'surprisal analysis' (brought forth in 1972 in collaboration with Richard Bernstein and Avinoam Ben-Shaul) became a major analytical tool in the study of reaction dynamics, and spread into diverse branches of science such as nuclear physics and molecular biology. Levineīs achievements in applying the ideas of quantum mechanics and thermodynamics culminated in their synthesis in his recent introduction of the algebraic approach to reaction dynamics, based on the maximum entropy principle. This new approach, too, has already gained followers in a variety of fields.