Matrix Isolation Vibrational Spectroscopy on Organic Molecules

Abstract

The early experiments on matrix isolation (M.I.) vibrational spectroscopy were made on small systems. This of course is essential in establishing the specific properties of matrices. However, most chemists deal with larger, organic, molecules. There thus is quite some interest in how M.I. can be used in problems involving these larger molecules. The area in which M.I. has given important contributions to organic chemistry can be split into two fields. The first of these makes use of the property for which the technique was actually invented by George Pimentel, i.e. the isolation of reactive species. A great deal of effort has been devoted to the study of transient organic molecules, generated either by photolysis, thermolysis or microwave discharge, before or after deposition of the matrix, or by cocondensing of the reactants. In this way unstable compounds such as radicals, or reactive species like butadiene or benzyne, or organic ions, both positive and negative, become available for vibrational study. An excellent review of this field has recently been published by I. R. Dunkin (1).