NiF2

Nickel(II) fluoride, NiF2, is an inorganic compound composed of nickel in the +2 oxidation state and fluoride ions. In its anhydrous form it appears as a pale green crystalline solid and is sparingly soluble in water. The compound crystallizes in a rutile-type structure, with Ni2+ coordinated by six fluoride ligands in octahedral geometry; each fluoride bridges between nickel centers to build a three-dimensional network.

NiF2 is typically prepared by direct fluorination of nickel metal or nickel oxide with fluorine gas at elevated temperatures. It can also be formed by fluorination of nickel salts under suitable conditions, or by decomposition routes that involve nickel-containing precursors and fluoride sources.

Chemically, NiF2 is relatively stable under dry conditions but is less stable in the presence of moisture, where hydrolysis can occur slowly. It is considered a poor conductor of electricity in the solid state and behaves as a typical ionic fluoride. Like other transition metal difluorides, NiF2 serves as a source of nickel in fluoride form for various synthetic applications.

Applications of NiF2 include use as a precursor to other nickel fluoride derivatives and as a reagent in solid-state synthesis for preparing nickel oxides and oxyfluorides. It has also been employed in studies of nickel-containing electrochemistry and as a starting material for materials used in fluoride-based catalytic or catalytic-related research.

Safety and handling notes: NiF2 is a nickel compound and fluoride compound, both of which can be hazardous if inhaled or ingested and may cause irritation to skin and eyes. Appropriate precautions, including protective equipment and proper disposal, should be taken when handling NiF2.