Since the first report of a single-molecule magnet (SMM) in 1993, there has been a great interest in developing these new materials. Single-molecule magnets are discrete molecules that show slow-magnetic relaxation below a critical blocking temperature due to a thermal barrier to spin alignment. For SMMs, the observed magnetic response is due to individual molecules. This opens to the door to potentially using SMMs as magnetic storage units, where individual molecules store individual pieces of data rather than the current need of larger, relatively speaking, transistors or bulk magnets. Single-molecule magnets have also been proposed to be useful as quantum computers, magnetic refrigerants, and an avenue to study physics occurring at the interface of the classical and quantum realms.
A great deal of research has been dedicated to improving SMM behaviors. Our research will attempt to utilize large, discrete metallamacrocycles known as metallacrowns (MC). These metallamacrocycles can be thought of as inorganic analogs of crown ethers, organic compounds that bind metal ions in the central cavity. In 1990/91, Pecoraro and co-workers described MCs as a macrocycle where the bond connectivity of the ring consists solely, or dominantly, of metal ions and heteroatoms (such as N or O atoms). Using certain organic compounds, known as ligands, and various metal ions, one can produce a wide variety of MCs with predictable geometries in quantitative yields. Our goal is to design and develop new MCs and to study their magnetic properties.
T. T. Boron, III, J. C. Lutter, C. I. Daly, C. Y. Chow, A. H. Davis, A. Nimthong-Roldán, M. Zeller, J. W. Kampf, C. M. Zaleski, V. L. Pecoraro. "The nature of the bridging ligand controls the single-molecule magnetic properties of DyX4M 12-Metallacrown-4 complexes." Inorg. Chem. 2016, 55, 10597 - 10607.
A. Deb; T. T. Boron, III; M. Itou; Y. Sakuria; T. Mallah; V. L. Pecoraro; J. E. Penner-Hahn. "Understanding Spin Structure in Metallacrown Single-Molecule Magnets using Magnetic Compton Scattering." J. Am. Chem. Soc. 2014, 136. 4889-4892.
M. R. Azar; T. T. Boron, III; K. A. Zegalia; G. M. Ferrence; M. Zeller; J. W. Kampf; V. L. Pecoraro; C. M. Zaleski. "Controllable Formation of Heterotrimetallic Coordination Compounds - Systematically Incorporating Lanthanide and Alkali Metal Ions into the Manganese 12-Metallacrown-4 Framework." Inorg. Chem. 2014. 53, 1729-1742.