Developing non-traditional methods for the design, synthesis, and analysis of spin crossover materials

Spin crossover (SCO) complexes are a promising class of smart material which can switch between high spin (HS) and low spin (LS) states upon application of external stimuli such as temperature, light, or pressure. This change in spin state is often accompanied by a dramatic change of colour as well as changes to the magnetic and structural properties making them useful in a wide range of applications such as sensors, actuators and barocaloric systems. As the search for new SCO materials with specific desirable properties continues, there is a need to expand the toolkit and explore new synthesis and crystallisation techniques. Non traditional techniques can also aid further understanding of the relationship between the structures of SCO materials and their SCO properties with the eventual end goal of being able to intelligently design a SCO material with the desired properties for a specific application. This along with investigating synthesis methods that are more industrially accessible are key factors that need to be addressed on the path to the real-world application of SCO materials.

Within this work, access to a variety of new SCO materials has been made possible using a mixture of traditional, non-traditional and solid-state methods such as AA, thin film synthesis, cocrystallisation and ENaCt. Several novel [MII(R-trz)3]SO4 and [Fe(ABPT)2(NCS)2] materials have been fully characterised and analysed to both better understand the relationship between their structure and their SCO properties, and also provide insight in the techniques used to make them.