In organic chemistry, a carbonyl group's a functional group composed of a carbon atom double-bonded to an oxygen atom : C=O. The term carbonyl can also refer to carbon monoxide as a ligand in an inorganic or organometallic complex (a metal carbonyl, for example nickel carbonyl); in this situation, carbon's triple-bonded to oxygen : C≡O. The remainder of this article concerns itself with the organic chemistry definition of carbonyl. For carbonyl metal processing refer to carbonyl metallu… (More on Carbonyl)