A new multi-switchable complex has been rationally assembled using a redox-active and strongly complexing bridging ligand. By simple oxidation/reduction, its magnetic properties can be tuned from a spin-crossover complex, to a single-molecule magnet with an S = 5/2 spin ground state (when once reduced) and to diamagnetic species when twice reduced. This work illustrates experimentally and theoretically how successive redox processes can increase the spin delocalization, and thus promote a dramatic enhancement of the intramolecular magnetic coupling through a bridging ligand, not only in its radical form. This general synthetic approach should help for the intentional design of new high-spin complexes and SMMs, but it could also be extended to systems with higher nuclearities and dimension- alities, for example to obtain high-temperature molecule- based magnets.
Xiaozhou Ma, Elizaveta A. Suturina, Siddhartha De, Philippe Négrier, Mathieu Rouzières, Rodolphe Clérac et Pierre Dechambenoit
Redox-Active Bridging Ligand as a Tool to Promote Spin Delocalization, High Spin Complexes and Magnetic Multi-Switchability
Angewandte Chemie International Edition – Avril 2018