Potassium Tetracyanonickelate (II) Hydrate

Dipotassium Nickel Tetracyanide hydrate (K₂[Ni(CN)₄]) is a yellow-orange, water-soluble coordination compound.  The Nickel-cyanide complex forms a square planar structure, which leaves available sites around the Nickel ion for coordination to other species.  Potassium Tetracyanonickelate is primarily used as a reagent for other Nickel complexes, as well as a reagent for electroplating.

For example, researchers from the University of Basilicata in Potenza, Italy used Potassium Tetracyanonickelate and Potassium Cyanocuprate(I) as the metal precursors to deposit a Ni-Cu alloy film on gold electrodes in a basic solution containing Sodium Hydroxide.  The resulting film electrocatalytically oxidized glucose and demonstrated strong electrochemical stability and longevity in basic media.

Potassium nickel cyanide can also be used as a synthetic precursor to prepare novel cyano complexes.  The cyano groups in tetracyanonickelate complexes can act as terminal or bridging ligands, resulting in complex architectures.  In a more recent example, researchers from Eskisehir Osmangazi University in Turkey grew crystals of two novel heteropolynuclear complexes.  They used Potassium Tetracyanonickelate as a starting reagent in the aqueous synthesis, along with Copper Chloride, Zinc Chloride, Cadmium Chloride, Nickel Chloride, and Potassium Cyanide.

1. Casella, I. G., & Gatta, M. (2002). Electrodeposition and Characterization of Nickel-Copper Alloy Films as Electrode Material in Alkaline Media. Journal of The Electrochemical Society, 149(10), B465. https://doi.org/10.1149/1.1504717
2. Fernelius, W. C., Burbage, J. J., & Ballou, N. E. (1946). Potassium Tetracyanonickelate(II). Inorganic Syntheses, 227–228. https://doi.org/10.1002/9780470132333.ch73
3. Sayin, E., Kürkçüoǧlu, G. S., Yeşilel, O. Z., Hökelek, T., & Büyükgüngör, O. (2014). One- and two-dimensional heteropolynuclear complexes with tetracyanonickelate(II) and 2-pyridinemethanol. Zeitschrift Fur Kristallographie – Crystalline Materials, 229(8), 563–572. https://doi.org/10.1515/zkri-2014-1756ja01476a007