Potassium tetracyanonickelate

Potassium tetracyanonickelate
Names
	Other names Potassium tetracyanonickelate(II); dipotassium tetracyanonickelate
Identifiers
CAS Number	14220-17-8;
3D model (JSmol)	Interactive image;
ChEBI	CHEBI:30071;
ChemSpider	11665648;
ECHA InfoCard	100.034.605
EC Number	238-082-7;
PubChem CID	61717;
UNII	BCX7A142U2;
CompTox Dashboard (EPA)	DTXSID40931384 ;
	InChI InChI=1S/4CN.2K.Ni/c41-2;;;/q4-1;2*+1;+2 Key: LXWJYIBQIPSFSE-UHFFFAOYSA-N;
	SMILES [K+].[K+].[N-]#C[Ni+2](C#[N-])(C#[N-])C#[N-];
Properties
Chemical formula	K2Ni(CN)4
Appearance	yellow solid
Hazards
	GHS labelling:
Pictograms
Signal word	Danger
Hazard statements	H300, H310, H330, H410
Precautionary statements	P260, P262, P264, P270, P271, P273, P280, P284, P301+P310, P302+P350, P304+P340, P310, P320, P321, P322, P330, P361, P363, P391, P403+P233, P405, P501
	Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

Potassium tetracyanonickelate (IUPAC: Potassium tetracyanido nickelate(II)) is the inorganic compound with the formula K₂Ni(CN)₄. It is usually encountered as the monohydrate but the anhydrous salt is also known. Both are yellow, water-soluble, diamagnetic solids. The salt consists of potassium ions and the tetracyanonickelate coordination complex, which is square planar. The [Ni(CN)₄]^2- anions are arranged in a columnar structure with Ni---Ni distances of 4.294 Å, which is well beyond the sum of the van der Waals radius of the nickel cation. This columnar structure resembles those of the other [M(CN)₄]^2- anions of the heavy congeners of the group 10 metals (M = Pd, Pt).