Nickel(II) acetate is the name for the coordination compounds with the formula Ni(CH3CO2)2·x H2O where x can be 0, 2, and 4.
The mint-green tetrahydrate Ni(CH3CO2)2·4 H2O is most common.
The compound can be prepared by treating nickel or nickel(II) carbonate with acetic acid: The mint-green tetrahydrate has been shown by X-ray crystallography to adopt an octahedral structure, the central nickel centre being coordinated by four water molecules and two acetate ligands.
[5] It may be dehydrated in vacuo, by reaction with acetic anhydride[6] or by heat.
[7] Nickel salts are toxic, carcinogenic and irritate the skin.