Direct Observation of Tunnelling Reactions by Matrix Isolation Spectroscopy

Abstract

Direct observation of tunnelling reactions of organic molecules under low-temperature matrix isolation conditions using infrared spectroscopy as a probing technique is described. The considered types of tunnelling-driven reactions include conformational rearrangements, as well as bond-forming/bond-breaking processes that take place either by hydrogen-atom tunnelling or heavy-atom tunnelling. The advantages and peculiarities of the matrix isolation method to allow for the direct observation of the tunnelling reactions are highlighted. Methods of in situ preparation of the reactants using photochemical approaches involving vibrational or electronic excitation are presented. Overview of the most recent publications describing observations of tunnelling isomerizations is included.