The salt [Na(cis-anti-cis-dicyclohexyl-18-crown-6)][Ni(dmit) ₂ ] ₄ ·2Me ₂ CO (dmit=1,3-dithiol-2-thione-4,5-dithiolate) has been prepared by electrocrystallisation and characterised by X-ray crystallography showing an unusual 1:4 cation:anion ratio. It consists of parallel stacks of [Ni(dmit) ₂ ] ^0.25– complexes separated by the Na ⁺ counter ion complexed by dicyclohexyl-18-crown-6 and two acetone molecules. The electrical conductivity, magnetic susceptibility and thermoelectric power of the salt have been measured and are consistent with semiconductor behaviour which is considered in conjunction with transfer integral calculations.