Abstract
Abstract Uncommon reversible guest‐induced metal‐hemilabile linker bond dynamics in MOF MFM‐300(Sc) was unraveled to switch on/switch off catalytic open metal sites. The catalytic activity of this MOF with non‐permanent open metal sites was demonstrated using a model Strecker hydrocyanation reaction as a proof‐of‐concept. Conclusively, the catalytic activity was evidenced to be fully reversible, preserving the conversion performance and structure integrity of MFM‐300(Sc) over multiple cycles. These experimental findings were corroborated by quantum‐calculations that revealed a reaction mechanism driven by the Sc‐open metal sites. This discovery paves the way towards the design of new effective and easily regenerable heterogeneous MOF catalysts integrating switchable metal sites.