Spectroscopy and Quantum-Dynamics: From Vibrations to Reactions

Abstract

The physical understanding of chemical reactivity builds on the connection between structural and dynamical molecular properties, such as the specific dynamical properties of functional groups which determine a molecule's chemical behavior. Studies of OH- and NH2 groups in different environments demonstrate how experiment and theory combine to draw a detailed picture of the molecular quantum-dynamics. The hydrogen motion in a series of model systems elucidates important aspects of the N/O/H chemistry, with implications for radical and atmospheric chemistry. In perfect analogy to the separation of electronic and nuclear motion in the Born-Oppenheimer approximation, characteristic motions of individual structural features are adiabatically separated from the overall system dynamics. This phenomenon of vibrational adiabaticity will play a central role in the understanding of the microscopic foundations of empirical structure–reactivity relationships.