SPIN-CROSSOVER IN A CATENANE SUPRAMOLECULAR SYSTEM

The compound [Fe(tvp)(2)(NCS)(2)]. CH3OH, where tvp is 1,2-di-(4-pyrid yl)-ethylene, has been synthesized and characterized by x-ray single-c rystal diffraction. It consists of two perpendicular, two-dimensional networks organized in parallel stacks of sheets made up of edge-shared [Fe(II)](4) rhombuses. The fully interlocked networks define large sq uare channels in the [001] direction. Variable-temperature magnetic su sceptibility measurements and Mossbauer studies reveal that this compo und shows low-spin to high-spin crossover behavior in the temperature range from 100 to 250 kelvin. The combined structural and magnetic cha racterization of this kind of compound is fundamental for the interpre tation of the mechanism leading to the spin crossover, which is import ant in the development of electronic devices such as molecular switche s.