Chemical properties: Due to the strong electron-withdrawing property of oxygen, nucleophilic addition reaction is easy to occur on carbon atoms. Other common chemical reactions include nucleophilic reduction and aldol condensation.

Structure and properties of metal carbonyl complexes

Metal carbonyl complexes are mostly insoluble in water. For example, the solubility of nickel tetracarbonyl in water is only 0.018g/100ml (at10 C), but it is soluble in most organic solvents, aqua regia and nitric acid.

The bond between carbonyl group and metal is the cooperative bond of feedback π bond and σ bond. The unbound electron pairs of carbon atoms form σ bonds with the mixed orbital domain of metal spd, while the metal-filled D orbital domain forms two π bonds with the π * anti-bond molecular orbital domain in the CO ligand. However, the formation condition of π bond is that the metal atom must have D orbital electrons, and the metal needs to have a low oxidation state (

In metal carbonyl complexes, the distance between metal and carbon atom is relatively short, generally less than1.8 & circ; 0.2 less than the distance between general metal and alkyl carbon. Acirc。