The nanoscopic v15 cluster: A unique magnetic polyoxometalate

In a review (Pope and M¨uller, 1991) about polyoxometalates (POMs) one can read: “Polyoxometalates form a class of inorganic compounds that is unmatched in terms of molecular and electronic structural versatility, reactivity, and relevance to analytical chemistry, catalysis, biology, medicine, geochemistry, materials science, and topology.” The importance of POMs for molecular magnetism and materials science can be recognized from the book by Gatteschi et al. entitled “Molecular Nanomagnets” (Gatteschi et al., 2006) (for general related books and reviews of the POM subject see also Refs. M¨uller et al., 1998; Clemente-Juan and Coronado, 1999). In this context, it was argued in the title of a subsequent review that POMs represent a “Source of Unusual Spin Topologies” (Gatteschi et al., 2001).