Encapsulation of a CrIII Single-Ion Magnet within an FeII Spin-Crossover Supramolecular Host.

Single functional molecules are regarded as future components of nanoscale spintronic devices. Supramolecular coordination chemistry provides unlimited resources to implement multiple functions to individual molecules. A novel coordination [Fe2 ] helicate exhibiting spin-crossover is demonstrated to be ideally suited to encapsulate a [Cr(ox)3 ]3- complex anion (ox=oxalate), unveiling for the first-time single ion slow relaxation of the magnetization for this metal. A possibility of tuning the dynamics of this relaxation as well as the performance of the CrIII center as qubit arises from the observation that metastable high spin FeII centers from the host can be generated by irradiation with green light at low temperature.