Soft-oxometalates beyond crystalline polyoxometalates: formation, structure and properties

Polyoxometalates (POMs), as the name suggests, are single molecular charged or uncharged clusters comprising many metal centres and oxygen atoms. They are crystalline. On the other hand, recently, a class of macroionic, superstructured assemblies of POMs has been found which is reminiscent of soft matter and has been proposed to be called Softoxometalates (SOMs). This highlight gives a personal account of our work with SOMs. Starting with a brief background and history of SOMs, we explore the reasons for their formation. Thereafter, we discuss the charge regulation mechanism for the stabilization of SOMs. A few case studies for the directed formation of large surface area, mesoscopic SOMs are also discussed. Thereafter, we discuss the effects of sound and light on SOMs. This highlight finally ends with a discussion on self-assembled pattern formation with oxometalates.