Oxygen Isotope Exchange Reactions of Organic Compounds

Abstract

Isotope exchange reactions are reversible chemical processes in which two isotopes C and C* of the same element exchange places. No net chemical change takes place in these reactions, but only interchange of the isotopic label occurs. The large majority of exchange reactions studied are those between organic compounds and water. These reactions significantly provide a great deal of information on the mechanisms of the reaction of organic compounds. The isotopic exchange of oxygen in organic compounds involves the use of O18. The isotopic exchange of O18 with organic compounds is important as a control in tracer studies, particularly in the systems of biological interest where water plays a prominent role. This chapter describes exchange reactions that deal with simple oxygen-containing organic molecules, such as alcohols, phenols, ketones, aldehydes, and carboxylic acids and their derivatives. It examines many organic derivatives of inorganic oxyacids, such as esters of phosphoric and sulphuric acids, for oxygen exchange with water. Few exchanges not involving water, such as the exchange of O18 between organic compounds and alumina and other metal oxides, are also presented.