Carbon monoxide can form carbonyls of several metals: iron, nickel, chromium, osmium, iridium, ruthenium, rhenium, cobalt, and tungsten.
What is a Carbonyl?
Carbon monoxide (CO) can form a carbonyl by surrounding a metal atom. For example, if 5 CO molecules surround a iron atom, this substance can become a liquid or gas with the iron 'dissolved' in it. Iron carbonyl is a straw coloured liquid at room temperature.
Industrial Uses of Carbonyls:
Running hot carbon monoxide over oxidized metals at pressure can reduce the metal ore into carbonyls. The mixed carbonyl, can then be cooked at various temperatures, to lay down pure metals in sequence. Thus it is a low temperature means of refining metals.
Poring a liquid carbonyl into a mold and heating it, can drive off the CO, leaving a solid metal part.
If a gaseous carbonyl is decomposed by a laser, 3D parts of metals can be build up, using 3D printer software.
Metal carbonyls can be used as a precursor to nano-particles.
"The Case For Mars, 2nd Edition", by Robert Zubrin, ISBN 9-781451-608113, pages 217 - 218.
// Discussion of ironpentacarbonyl.