Surprisingly Large Electronic g-Factors in p-Doped Lead Clusters
A Magnetic Molecular Beam Deflection Study Coupled with Modern Quantum Chemistry
2023/02/01
Molecular Magnetism is a thriving field of research with remarkable discoveries being made with single-molecule magnets where d- and f-block elements serve as paramagnetic centers. Tetrel clusters p-doped with elements of the triel group also state magnetically highly relevant systems. If lead is chosen as tetrel cage element, the endohedral clusters are found to exhibit peculiar spin-orbit coupling effects with strongly impacted electronic g-factors.
It is reported on huge electronic g-factors of g=3.5-4.0 which were experimentally observed for the endohedral clusters AlPb12 and InPb12 and are so far unreached by molecules solely based on main group elements as well as most single-ion magnets of high symmetry. In contrast, GaPb12 surprisingly possesses a g-factor of less than 2.0. This tunable behavior is investigated further by constructing a qualitative model based on perturbation theory and by performing multireference ab initio calculcations.
The large g-factors are found to be a consequence of a particularly strong spin-orbit coupling in conjunction with a pyritohedral molecular symmetry. Contrarily, the g-factor in GaPb12 is quenched due to a Ga s orbital ground state that is subject to the d-block contraction resulting in an icosahedral symmetry. The results do not only disclose a deep understanding of the electronic structure, but also provide an insight into the fascinating interplay of metal dopant and tetrel ligands being of fundamental relevance in molecular magnetism.
