Guest-Switchable Multi-Step Spin Transitions in an Amine-Functionalized Metal-Organic Framework

摘要

Materials with hysteretic multi-step spin-crossover (SCO) have potential application in high-order data storage. Here, an unprecedented hysteretic four-step SCO behavior with the sequence of HS <-> HS0.25LS0.75 <-> HS0.5LS0.5 <-> HS0.75LS0.25 <-> HS is found in a three-dimensional (3D) HofNman-type metal-organic framework (MOF), which is evidenced by magnetic, differential scanning calorimetry, and crystal data. Further experiments involving guest exchange leads to the first reversible modulation of four-, two-, and one-stepped SCO behaviors, which provides a new strategy for developing multi-step SCO materials.