Unusual Co-ordination of α-Phenylbutylamine with Nickel Thiocyanate as a Result of Clathration

NUMEROUS α-arylalkylamines co-ordinate with nickel (II) thiocyanate to form complexes of the type [Ni(NCS) 2 (amine) n ], where n is 2 or 4 (ref. 1). The complexes for which n is 2 are light green and are insoluble in most solvents. These properties and their infra-red spectra 2 suggest that they have a polymeric octahedral structure with nickel atoms bridged through the thiocyanato groups. The complexes for which n is 4 are blue and are readily soluble in many solvents, such as methanol or chloroform. However, they are not soluble in water, in which they undergo hydrolysis with formation of nickel hydroxide. Our X-ray diffraction investigations 3 , which are still in progress, have shown that these complexes are trans-octahedral with the thiocyanato groups linked through their nitrogen atom.