K2NiCN4

K2NiCN4, also known as potassium tetracyanonickelate(II), is an inorganic coordination compound. It consists of potassium cations (K+) and the tetracyanonickelate(II) anion ([Ni(CN)4]2-). The nickel atom in the complex is in the +2 oxidation state and is surrounded by four cyanide ligands (CN-) in a square planar geometry.

This compound typically appears as a yellow crystalline solid. It is soluble in water, forming a solution containing potassium ions and the [Ni(CN)4]2- complex ion. The tetracyanonickelate(II) ion is known for its stability.

K2NiCN4 can be synthesized by reacting nickel(II) salts with potassium cyanide in aqueous solution. The reaction involves the formation of the coordination complex where cyanide ions act as ligands, donating electron pairs to the central nickel ion.

The compound has been studied for its magnetic properties. Nickel(II) in a square planar environment is typically diamagnetic. K2NiCN4 exhibits diamagnetic behavior, consistent with its electronic configuration. Its applications are limited, but it may be used in certain chemical research contexts or as a precursor for other nickel compounds.