Layered Spin‐Crossover Metal‐Organic Frameworks for Light‐Induced Control of Two‐Dimensional Quantum Materials

Metal‐organic frameworks (MOFs) are widely explored for gas separation, catalysis, or energy storage, yet their integration with other electronically functional materials remains largely unexplored. Here, we integrate the layered Hofmann‐type spin‐crossover (SCO) MOF {Fe II (pyS 2 Et) 2 [Pt II (CN) 4 ]} into electrical nanodevices to control the properties of two‐dimensional (2D) quantum materials. Our molecular approach exploits the stimuli‐responsive nature of SCO‐layered materials as switchable building blocks. We demonstrate selective modulation of the electronic transport in van der Waals heterostructures interfacing SCO with 2D quantum materials (few‐layer graphene, magnetic CrSBr, superconducting NbSe 2 ) through the strain induced via thermal and light‐induced spin transitions. In graphene, the conductivity is selectively switched by light. In spin‐valves based on CrSBr bilayers, the MOF triggers magnetic hysteresis (absent in pristine CrSBr) and enables tunable non‐volatile zero‐field memory. In NbSe 2 , light modulates the superconducting critical current and transition temperature. These results establish layered stimuli‐responsive SCO MOFs as active molecular control elements for 2D quantum materials, providing a route to strain‐mediated control of electronic, magnetic, and superconducting functionalities, and extending MOF‐based architectures beyond traditional porous‐matter applications toward multifunctional electronics and spintronics.