Structural, Electronic, and Magnetic Properties of Neutral Borometallic Molecular Wheel Clusters

Atomic clusters exhibit properties that fall between those found for individual atoms and bulk solids. Small boron clusters exhibit planar and quasiplanar structures, which are novel materials envisioned to serve as a platform for designing nanodevices and materials with unique physical and chemical properties. Through past research advancements, experimentalists demonstrated the successful incorporation of transition metals within planar boron rings. In our study, we used first-principles calculations to examine the structure and properties of neutral boron clusters doped with transition metals, denoted as TMB and TMB₂, where TM = Ti, Cr, Mn, Fe, Co, Nb, or Mo and n=8-10. Our calculations show that the TMB₂ structures, which involve sandwiching metal atoms between two rings (called the drum configuration), and clusters with the single ring configuration, TMB, are stable. These clusters typically have relatively large HOMO-LUMO energy gaps, suggesting high kinetic stability and low chemical reactivity. Moreover, the clusters display interesting magnetic properties, determined not only by the metal atoms but also by the induced magnetism of the boron rings. These structures have potential applications in spintronics and sensing. This work also provides a basis for studying magnetism in the one-dimensional limit.