Emerging trends in spin crossover (SCO) based functional materials and devices

The design and synthesis of functional molecules with controllable properties are at the forefront of modern materials chemistry research due to their diverse applicability, especially in device miniaturization. Spin crossover (SCO) complexes can be switched between low (LS) and high spin (HS) magnetic states with the help of an external perturbation, and are promising candidates for the realization of molecule-based electronic and spintronic components, such as switching and memory elements. Although the area is relatively old and a multitude of SCO active transition metal complexes of d4-d7 electronic configuration have been reported, the field continues to grow, and several interesting research directions have emerged. In this context, the present review attempts to give a concise overview of recent trends in SCO research. Attempts devoted towards rendering multifunctionality to the SCO systems in order to bridge the gap between laboratory and reality, and efforts made to study spin state dependence of physical property modulation such as electrical conductance from single molecule level to bulk, prerequisite for the realization of SCO-based devices, are emphasized by discussing the most relevant past and recent literature.