Probing the structural evolution of ruthenium doped germanium clusters: Photoelectron spectroscopy and density functional theory calculations.

Yuanyuan Jin,Weijun Zheng,Shengjie Lu,Hongguang Xu,Xiaoyu Kuang,Cheng Lu,Chuanzhao Zhang,Andreas Hermann

doi:10.1038/srep30116

Abstract

We present a combined experimental and theoretical study of ruthenium doped germanium clusters, RuGen− (n = 3–12), and their corresponding neutral species. Photoelectron spectra of RuGen− clusters are measured at 266 nm. The vertical detachment energies (VDEs) and adiabatic detachment energies (ADEs) are obtained. Unbiased CALYPSO structure searches confirm the low-lying structures of anionic and neutral ruthenium doped germanium clusters in the size range of 3 ≤ n ≤ 12. Subsequent geometry optimizations using density functional theory (DFT) at PW91/LANL2DZ level are carried out to determine the relative stability and electronic properties of ruthenium doped germanium clusters. It is found that most of the anionic and neutral clusters have very similar global features. Although the global minimum structures of the anionic and neutral clusters are different, their respective geometries are observed as the low-lying isomers in either case. In addition, for n > 8, the Ru atom in RuGen−/0 clusters is absorbed endohedrally in the Ge cage. The theoretically predicted vertical and adiabatic detachment energies are in good agreement with the experimental measurements. The excellent agreement between DFT calculations and experiment enables a comprehensive evaluation of the geometrical and electronic structures of ruthenium doped germanium clusters.

Highlights

Structures and are unsuitable as a building block of self-assembly materials[15,16]
Based on the anion photoelectron spectroscopy in combination with density functional theory (DFT) calculations, Deng et al.[11] studied the structural, electronic and magnetic properties of VGen−/0 (n = 3–12) clusters and suggested that the endohedral structures occur from n = 9 and a D3d distorted hexagonal prism cage structure is formed at n = 12
As an effort to address the above questions, here we report a combined photoelectron spectroscopy and DFT study on Ru-doped germanium clusters: RuGen− and RuGen (n = 3–12)

Summary

Introduction

Structures and are unsuitable as a building block of self-assembly materials[15,16]. In order to generate and stabilize Ge cage structures, numerous experimental and theoretical investigations have been performed on transition metal (TM)-doped germanium clusters, similar to the case of TM-doped silicon clusters[11,12,17,18,19,20,21,22,23,24,25]. The structures of RuGen− and RuGen are assigned by the comparison of the theoretical simulations and experimental measurements. The theoretical VDE and ADE values of the global minimum anions are listed, in comparison with the experimental data.

Results

Conclusion