It is used in electroplating and as a catalyst for organic conversions, for example in chemo-selective thioacetalization of aldehydes. In combination with lithium aluminum hydride, it serves as a reducing agent for alkenes, alkynes, and organic halides; it can cleave N-O bond and open epoxides. It is a precursor to several nickel-phosphine complexes, such as bis(triphenylphosphine)nickel(II) chloride, which are used in alkyne trimerizations, carbonylations, and as catalysts in organic reactions such as Suzuki-Miyaura cross coupling reactions as an alternative to palladium(0) catalysts. It is the precursor to acetylacetonate complex of Ni, used for producing 1,5-cyclooctadiene complex, an important reagent in organonickel chemistry. It can be used to prepare the sandwich compound nickelocene through dimethoxyethane complex of nickel chloride.
It crystallises from dilute HCl to form the green hexahydrate. At 70o this dehydrates to the tetrahydrate, and at higher temperatures it forms the anhydrous salt. It sublimes in yellow hexagonal scales in a stream of HCl. Store it in a desiccator as it is deliquescent. [Hart & Partington J Chem Soc 104 1943.]
