Organometallic chemistry - Metal carbonyls

The discovery of nickel carbonyl by Langer and Mond was a matter of chance, and understanding the mode of bonding between carbon monoxide and the transition metal took many years. As a result, for a long time this compound presented itself as a curiosity, especially as the simple application of Werner's principles was not sufficient to adequately explain its characteristics. Chemists then tried to prepare analogous species involving other metals.

The synthesis method is not unique and several routes have been developed. Moreover, it soon became apparent that not all these metal carbonyls contain a single metal atom.

The aim of this article is precisely to describe these different metal carbonyls and their preparations. The nature of the bonding will be discussed. Finally, it will be shown how polymetallic edifices can be constructed and what bonding modes are required to explain their formulae.