Platinum Metals Review - Volume 44, Issue 3, 2000

Acetic acid is an important industrial commodity chemical, with a world demand of about 6 million tonnes per year and many industrial uses. The preferred industrial method for its manufacture is by the carbonylation of methanol and this accounts for approximately 60 per cent of the total world acetic acid manufacturing capacity. The carbonylation of methanol, catalysed by rhodium, was invented by Monsanto in the 1960s and for 25 years was the leading technology. In 1996 a new, more efficient, process for the carbonylation of methanol was announced by BP Chemicals, this time using an iridium catalyst. This article describes the new process and looks at the ways in which it improves upon the prior technology.

In recent years there has been increased interest in the tobacco industry driven primarily by high-profile disclosures made during health-related litigation in the United States of America. Over the years, tobacco companies and others have filed many patents aimed at reducing the concentrations of known harmful chemicals in tobacco smoke. The literature contains a number of articles and patents which mention the potential for platinum group metals to decrease these harmful effects. This review attempts to summarise the published work in which the platinum group metals have been discussed with respect to cigarette use.

In the first part of this review, published in the April issue of this Journal, the main catalyst systems used for metathesis catalysis were examined, and followed by a short report on metathesis activity and selectivity. In this second part, attention is now drawn to specific applications of platinum group metals metathesis catalysts, in particular, to a variety of ring-closing metathesis reactions. The last part of this review will be published in the October issue of this Journal.

On 22nd July 1799 the definitive standards of the metric system, the platinum metre and the platinum kilogramme, were ceremonially deposited in the French National Archives (1), and on 10th December 1799 a law was passed confirming their status as the only legal standards for measuring length and mass in France (2). The accurate determination of these standards had occupied a number of outstanding French scientists for ten years, using elaborate equipment partly made from platinum by Etienne Lenoir, a skilled instrument maker. This work had been undertaken after more than a century of discussion. The events surrounding this momentous occasion which now affects all our everyday lives are described here.