Spin Crossover

Nanoporous molecular framework materials have received widespread attention due to their immensely rich host-guest chemistry and exceptional chemical versatility. The field has undergone extensive advancement in recent years with efforts to design framework materials with very specific functions and properties. The incorporation of spin crossover (SCO) centres into such framework structures opens the question of whether molecular guests may be encapsulated into these materials, and whether the reversible exchange of these guests may provide a novel mechanism to perturb the electronic switching properties (and vice versa). Magnetic studies, thermogravimetric analysis, X-ray and neutron diffraction, photomagnetic studies, guest sorption studies, IR and RAMAN spectroscopy are but a few of the techniques being used to elucidate the guest-uptake and guest-dependant SCO properties of such materials.

SCO may be accompanied by drastic changes in colour, magnetism or structure and thus materials displaying such behaviour may have applications in optical displays, molecular sensing, and data storage. Nanoporous framework materials are valuable to study due to their intrinsic ability to combine two or even three properties of interest in the one multi-functional material. Further to this, the interplay between such properties opens up interesting research prospects.

The research avenue of multi-functional materials allows for potential applications in many areas. For example, it can be envisaged that SCO materials may be used for information storage and as optical and magnetic components. Combining SCO functionality and nanoporosity allows the ability to tune the material (using host-guest chemistry) for these functions, as well as opening up new applications in molecular sensing.