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

The reaction of CoBr2, 1,2-di(4H-1,2,4-triazol-4-yl)diazene (bta) and KSCN yielded a one-dimensional coordination polymer [Co(SCN)2(bta)(H2O)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.