Molecular Mechanisms of Spin Crossover in the {Fe(pz)[Pt(CN)4]} MOF upon Guest Adsorption

Metal-organic frameworks (MOFs) that exhibit spin-crossover behavior have attracted much interest because of their potential technological applications. A key parameter that characterizes these materials is the transition temperature, defined as the temperature at which equal populations of low-spin and high-spin species are present. It was experimentally reported that the transition temperature of [Fe(pz)Pt(CN)4] can be controlled by the adsorption of guest molecules [1]. In this study, we report on Monte Carlo/molecular dynamics simulations aimed at characterizing the spin-crossover properties of [Fe(pz)Pt(CN)4] upon adsorption of chemically and structurally different guest molecules. We develop a molecular-level picture of spin-crossover behavior in [Fe(pz)Pt(CN)4] [2,3] and determine the physical mechanisms responsible for the stabilization of the low-spin state [4]. We also demonstrate that the variation of the spin-crossover temperature of [Fe(pz)Pt(CN)4] upon guest adsorption can be used to detect toxic gases.
[1] M. Ohba et al., Angew. Chem. Int. Ed. 48, 4767 (2009).
[2] C.H. Pham, J. Cirera, F. Paesani, J. Am. Chem. Soc. 138, 6123 (2016)
[3] C.H. Pham, F. Paesani, J. Phys. Chem. Lett. 7, 4022 (2016)
[4] C.H. Pham, F. Paesani, to be submitted.