Recent advances in guest effects on spin-crossover behavior in Hofmann-type metal-organic frameworks

The incorporation of spin-crossover (SCO) properties into metal-organic frameworks (MOFs) is an appealing subclass of multifunctional MOFs with potential applications in molecular sensing. This review focuses on the design of SCO Hofmann-type MOFs, with emphasis on the guest effect on their SCO properties. The influences of guest size, dielectric constant, π⋯π interaction, hydrogen bonding interactions, weak X⋯M′ covalent bonding, and chemical reaction on the SCO properties of Hofmann-type MOFs are systematically explored. Further enhancements of sensing properties are also illustrated.