Tetrahedral Pt₁₀^– Cluster with Unique Beta Aromaticity and Superatomic Feature in Mimicking Methane

Abstract

Utilizing a customized metal cluster source in tandem with a flow tube reactor and a reflectron time-of-flight mass spectrometer, we have obtained well-resolved pure metal clusters Pt n − and observed their gas-phase reactions with a few small gas molecules. Interestingly, the remarkable inertness of Pt 10 − was repeatedly observed in different reactions. Meanwhile, we have determined the structure of Pt 10 − within a regular tetrahedron. Considering that Pt possesses 5d 9 6s 1 electron configuration, the tetrahedral Pt 10 − exhibits unexpected stability at neither a magic number of valence electrons nor a shell closure of geometric structure. Comprehensive theoretical calculations unveil the stability of Pt 10 − is significantly associated with the allmetal aromaticity. In addition to the classical total aromaticity, which is mainly due to 6s electrons, there is unique beta-aromaticity ascribed to spin-polarized beta 5d electrons pertaining to singly occupied multicenter bonds. Further, we demonstrate the superatomic feature of such a transition metal cluster Pt 10 − , as Pt 6 @Pt 4 − , in mimicking methane.

Plasma‐Assisted Dinitrogen Activation on Small Cobalt Clusters: Co4N9+ with Enhanced Stability

“…It is worth mentioning that the HOMO‐LUMO gaps do not guarantee cluster stability, but could be associated with electronic donation and subsequent N 2 coordination. In general, the alpha HOMO‐LUMO gap is emphasized for naked metal clusters as well as their complexes, the beta‐electrons could significantly contribute to the covalent bonding and even electron delocalization in forming superatomic states [21] . For example, the vertcal ionization energy (VDE) of cationic Co 4 + is up to 11.57 eV, whereas the TD‐DFT calculated first excitation energy for Co 4 + cluster is as small as 0.19 eV which is associated with the excitation of β HOMO→LUMO+1.…”

“…In general, the HOMO-LUMO gap is emphasized for naked metal clusters as well as their complexes, the beta-electrons could significantly contribute to the covalent bonding and even electron delocalization in forming superatomic states. [21] For example, the vertcal ionization energy (VDE) of cationic Co 4…”

On the Nature of Three-Atom Metal Cluster Catalysis for N2 Reduction to Ammonia

“…The chemical bonding properties were analyzed using the Amsterdam density functional (ADF 2021.104) program with spin-unrestricted calculations . The PBE exchange–correlation functional and TZ2P Slater basis set were employed to explore the orbital interactions of the N 2 adsorption on M 3 clusters and their fragments by taking into consideration the zero-order regular approximation. , …”

An Open-Shell Superatom Cluster Ta10– with Enhanced Stability by United d–d π Bonds and d-Orbital Superatomic States

“…Metal clusters at the subnanoscale bridge the gap between atoms and macroscopic materials, providing a new perspective on electronic states and orbital theory. − The well-established jellium model assumes that electrons are uniformly delocalized according to the near free electron gas (NFEG) theory of metals, , with highly degenerate electronic states within the spherical potential functions, shedding light on the physics and chemistry of superatoms. − It is predicted that magic numbers of inert superatom clusters (namely, superatomic noble gases) can be experimentally observed when the jellium orbitals are filled following the sequence 1S 2 , 1P 6 , 1D 10 , 2S 2 , 1F 14 , 2P 6 , 1G 18 , 2D 10 and so on. A great success of this principle has been attained for the s- and p-block main-group metal clusters and coinage metal clusters, such as the observation of the magic-number clusters Na 20 , Al 13 – , and Ag 17 – with 20, 40, and 18 electrons, respectively. − Notably, the Clemenger–Nilsson model allows for rearranged electronic shells from prolate to oblate, enabling us to rationalize superatoms with nonspheroidal geometries − and even those of doped metal clusters. − …”