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Structural Stability and Evolution of Medium-Sized Tantalum-Doped Boron Clusters: A Half-Sandwich-Structured TaB12 – Cluster
Version 2 2018-10-01, 19:18
Version 1 2017-12-11, 18:50
journal contribution
posted on 2018-01-02, 00:00 authored by Bo Le Chen, Wei Guo Sun, Xiao Yu Kuang, Cheng Lu, Xin Xin Xia, Hong Xiao Shi, George MaroulisTransition-metal (TM)-doped boron
clusters have received considerable attention in recent years, in
part, because of their remarkable size-dependent structural and electronic
properties. However, the structures of medium-sized boron clusters
doped with TM atoms are still not well-known because of the much increased
complexity of the potential surface as well as the rapid increase
in the number of low-energy isomers, which are the challenges in cluster
structural searches. Here, by means of an unbiased structure search,
we systematically investigated the structural evolution of medium-sized
tantalum-doped boron clusters, TaBn
0/– (n = 10–20). The results
revealed that TaBn
0/– (n = 10–15) clusters adopt half-sandwich
molecular geometries, with the notable exception of TaB10
–, while for n = 16–18
and 19–20, the lowest-energy clusters are characterized by
drum-type geometries and tubular molecules with two B atoms on the
top, respectively. Good agreement between the calculated and experimental
photoelectron spectra strongly support the validity of our global
minimum structures. Molecular orbital and adaptive natural density
partitioning analyses indicate that the enhanced stability of half-sandwich
TaB12
– is due to the strong interaction
of the Ta atom (5d orbitals) with surrounding B atoms (2p orbitals)
and σ B–B bonds in the B12 moiety.