Humidity-Sensitive Magnet Composed of a Cyano-Bridged CoII–NbIV Dimetallic Assembly

Nanoporous magnetic materials composed of metal-assembled complexes are expected to exhibit chemical sensitivity. In this work, we observed a humidity-induced reversible change between ferromagnetism and antiferromagnetism in a new type of a cobalt octacyanoniobate based magnet in the high-humidity region. This humidity response is caused by the adsorption and desorption of non-coordinated water (so-called zeolitic water) molecules in the interstitial site. Such a phenomenon is achieved by the structural flexibility of an octacyanometalate-based magnet.