ABSTRACT
Recent spectroscopy based on various laser techniques has been making great progress as a tool for the direct study of the dynamics of molecules. These include femtosecond probe of chemical reaction, 1 ) single molecule spectroscopy, 2 , 3 ) and spectroscopy of chaos related dynamics. 3 , 4 ) Yet another example of remarkable experimental advance can be found in what is called transition-state spectroscopy. 5 ) The transition state was only a theoretical notion before, but some have now been identified experimentally. Several different kinds of experiments have been devised to observe transition states directly. Among others, dissociative photodetachment 5 ) is one of the most promising experimental methods, in which an electron of an inion molecule is photodetached and thereby the state is pumped up to the transition-state region of a reactive potential surface.
