Citation | The candidate has made outstanding contributions to the understanding of molecular processes by his wide-ranging studies of gas-phase chemical kinetics, molecular reaction dynamics and energy transfer. He has been among the first to exploit and develop new spectroscopic techniques and combinations of techniques to measure rate and state-to-state data for elementary processes. In addition, the candidate has demonstrated a keen awareness of the interaction between theory and experiment. Not only can he claim a number of valuable theoretical contributions himself, but his choice of systems for experimental study and the interpretation of the results display a sharp insight into the fundamental nature of molecular processes and what determines their dynamics. Although other examples might be given, this facet of the candidate's work can be illustrated by reference to his work on radical-radical processes. In this field, among other contributions, (i) he first developed direct methods for studying the kinetics of radical-radical reactions, (ii) he appreciated the importance in radical-radical collisions of the existence of multiple potential energy surfaces, (iii) he recognised that the relationship between reactive and inelastic processes provides a means of estimating reaction rate constants for conditions where they cannot be measured directly, (iv) he carried out some of the first state-to-state studies of such reactions, and (v) he is now examining the kinetics of radical-radical reactions at much lower temperatures then have been achieved before, both as a test of theory and because of astrochemical interests. |