Mimicking the magnetic properties of rare earth elements using superatoms

Abstract

Rare earth elements (REs) consist of a very important group in the periodic table that is vital to many modern technologies. The mining process, however, is extremely damaging to the environment, making them low yield and very expensive. Therefore, mimicking the properties of REs in a superatom framework is especially valuable but at the same time, technically challenging and requiring advanced concepts about manipulating properties of atom/molecular complexes. Herein, by using photoelectron imaging spectroscopy, we provide original idea and direct experimental evidence that chosen boron-doped clusters could mimic the magnetic characteristics of REs. Specifically, the neutral LaB and NdB clusters are found to have similar unpaired electrons and magnetic moments as their isovalent REs (namely Nd and Eu, respectively), opening up the great possibility in accomplishing rare earth mimicry. Extension of the superatom concept into the rare earth group not only further shows the power and advance of this concept but also, will stimulate more efforts to explore new superatomic clusters to mimic the chemistry of these heavy atoms, which will be of great importance in designing novel building blocks in the application of cluster-assembled nanomaterials. Additionally, based on these experimental findings, a novel “magic boron” counting rule is proposed to estimate the numbers of unpaired electrons in diatomic LnB clusters.

Direct experimental observation of weakly-bound character of the attached electron in europium anion

“…We explored this question by utilizing the photoelectron spectroscopy, which has been proven to be a powerful approach to directly probe the electronic properties of atoms and clusters2728293031323334353637383940. Herein, we present direct experimental observations on the features of the electron-atom interaction in Eu − .…”

On reactivity of superatom Be8C with nucleophiles to produce hydrogen

“…This finding explains the Pt‐like behavior of tungsten carbide in surface catalysis [22]. Later, they went further and provided experimental confirmation of using superatomic clusters to mimic the magnetic properties of rare earth elements [23]. Meanwhile, Khanna, and co‐workers also worked on identifying superatom clusters with high spin magnetic moments, and their efforts have yielded fruitful results.…”

Observation of “Outlaw” Dual Aromaticity in Unexpectedly Stable Open-Shell Metal Clusters Caused by Near-Degenerate Molecular Orbital Coupling

“…Compared with the traditional aromaticity in organic compounds (mainly the π-aromaticity, as in benzene), the introduction of metals, especially the d-and f-block elements, into the aromatic systems could not only form high-spin species but also increased the diversity of aromaticity remarkably, in particular, δand hybridized aromaticity. 20,21 This fact and our continuous interest in seeking novel properties of clusters [22][23][24][25][26] inspired us to explore whether all-metal clusters are appropriate candidates, able to overcome the challenge mentioned above of possessing dual aromaticity in both the ground and the excited states.…”