Forty years of plutonium chemistry: the beginnings

The first isolation of a chemical compound of plutonium (a fluoride) took place on August 20, 1942 and the first weighing of a pure compound (2.77 micrograms of the dioxide) on September 10, 1942. Thus this Symposium marks quite precisely the 40th anniversary of these events, the beginnings of the investigation of the macroscopic (non-tracer) chemical properties of this important synthetic element. The immediately following ultramicrochemical studies led to a definition of the IV and VI oxidation states, some properties of the metallic state, the synthesis and characterization of numerous solid compounds and the crucial testing of the first method devised for its separation and isolation in pure form after its production in nuclear chain reaction. Later work with larger amounts, available as the result of its production in a nuclear reactor, made it possible to characterize the III and V oxidation states and many more compounds. 7 references, 6 figures