Magnetic variation induced by structural transformation from coordination chains to layers upon dehydration.

The reaction of CoBr(2), 1,2-di(4H-1,2,4-triazol-4-yl)diazene (bta) and KSCN yielded a one-dimensional coordination polymer [Co(SCN)(2)(bta)(H(2)O)(2)] with water molecules coordinated to the metal ions. After dehydration at 100 °C, the compound transformed into a layered coordination polymer [Co(SCN)(2)(bta)], whose structure was determined by powder X-ray diffraction based on the single-crystal structure of another layered coordination polymer [Cd(SCN)(2)(bta)]. Interestingly, a magnetic variation from a simple paramagnet to an antiferromagnetic ordered phase of a single-chain-magnet that exhibits both metamagnetic behaviour and slow magnetic relaxation was observed upon the dehydration process.