Deep blue tetrachloronickelate(II) salts of 1-alkyl-3-methylimidazolium cations [C n mim] + with intermediate chain lengths (n=5, 7, 8 and an n=4/6 mixture) have been prepared from imidazolium chlorides and NiCl 2 . They are liquid at ambient temperatures (ca. 20°C) and above, and display viscosities and thermal stability comparable to related [BF 4 ] − compounds. The similarities may reflect the compensating effects of the dinegative charge of the [NiCl 4 ] 2− ion and its larger size.