Preparation, structure and properties of [Na (cis-anti-cis-dicyclohexyl-18-crown-6)][Ni (dmit)(2)](4) center dot 2Me(2)CO

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 elect rocrystallisation and characterised by X-ray crystallography showing an unu sual 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 dicycloh exyl-18-crown-6 and two acetone molecules, The electrical conductivity, mag netic susceptibility and thermoelectric power of the salt have been measure d and are consistent with semiconductor behaviour which is considered in co njunction with transfer integral calculations.