Platinum Metals Review - Volume 35, Issue 2, 1991

In order to meet urgent needs in aerospace research, an electrical resistance strain gauge of palladium-13 weight per cent chromium alloy is being developed both in fine wire and thin film forms at the NASA Lewis Research Center. The wire strain gauge has platinum wire wound around the gauge grid to serve as the temperature compensator, and is coated with a special alumina-based overcoat. This gauge has a sufficiently small apparent strain, with good reproducibility between thermal cycles to 800°C. The apparent strain of the gauge can therefore be corrected within a reasonable error up to this temperature. The thin film gauge, which provides a means for non-intrusive strain measurements, demonstrates the possibility of extending the use of this palladium alloy to approximately 1000°C.

In recent years much interest has been focused on carbonylation reactions in aqueous or biphasic systems catalysed by platinum group metals complexes. This is due to the reactivity of platinum group metals ions as catalysts designed to activate small molecules. When used in C, chemistry a variety of reactions can be catalysed by these complexes, in particular by ruthenium complexes. Ruthenium has several oxidation states and co-ordination numbers, and is relatively cheap. Additionally, ruthenium catalysts are stable and their reaction conditions are usually mild, making them excellent for homogeneous catalysis. Various reactions of ruthenium carbonyl complexes and ruthenium saloph dichloride complexes with carbon monoxide have been investigated in this laboratory, and are considered here.

Dedicated to Henri Moissan on the occasion of the one hundredth anniversary of his discovery of the first fluorophosphine platinum complex, this review describes the recent interest, and developments in fluorophosphines as ligands for platinum group metals. The synthesis, structure, reactions, stability, and the potential of these compounds as homogeneous and heterogeneous catalysts are the main features of this article.

Attendance at the 1991 Society of Automotive Engineers International Congress and Exposition held in Detroit, Michigan, U.S.A. from 25th February to 1st March, 1991, was affected by the conflict in the Middle East; in particular representation front Europe and Japan was considerably less than usual. Nevertheless there was an extensive programme of technical papers covering many aspects of the motor car in a number of parallel sessions, several of which covered emissions technology.

As a general rule, this Journal does not aim to report on the occurrence or genesis of the platinum-group elements. None the less, the following account is published in the belief that it will interest many readers, and inform them of important platiniferous deposits about which little has been written in Western literature. During August and September, 1990, Professor G. von Gruenewaldt, Director of the Institute for Geological Research on the Bushveld Complex at the University of Pretoria, spent four weeks visiting platinum producing areas in the U.S.S.R. as a guest of that country’s Academy of Sciences; his report follows.