Hard single-molecule magnet behavior and strong magnetic coupling in pyrazinyl radical-bridged lanthanide metallocenes

The realm of single-molecule magnets (SMMs), a frontier where lanthanides promise unparalleled magnetic properties, has garnered substantial interest due to its potential application in high-density information storage. These molecules exhibit magnetic memory at the molecular scale and can act as nanoscopic analogs to classical magnets, materials that have found a wide range of contemporary applications. Although lanthanides possess unquenched anisotropy, establishing strong magnetic communication between multiple metals for optimal performance is challenging. To overcome this communication barrier, herein, we describe the successful introduction of pyrazine radical linkers into oligo- and polynuclear lanthanide complexes that exhibit unprecedented strong magnetic coupling and hard SMM behavior. These materials not only stand as achievements in synthetic chemistry but may also serve as blueprints for the design of novel magnetic materials.