Carbon monoxide is the most common p-acceptor ligand in organometallic chemistry. Homoleptic carbonyls (a complex only containing the carbonyl ligand) ca be prepared for most of the d-block metals. They are useful as precursors to many other organometallic complexes and the bonding of the carbonyl to the metal centre activates in such a way that it can undergo organic chemistry which otherwise would not be easily possible. Below are some examples of the first row d-block elements. Across the group the carbonyl ligand is able to stable low oxidation states at the metal centre through its ability to acceptor electron density. Each of the complexes are 18e electron species. Click on each line drawing to view it s 3D structure.
The bonding pattern is simply illustrated here.
Other molecules of the month compounds