Odd-even effect of the number of free valence electrons on the electronic structure properties of gold-thiolate clusters |
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Authors: | Yanle Li Vytor Oliveira Dieter Cremer Zijia Chen |
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Institution: | 1. Key Laboratory of Mesoscopic Chemistry of MOE, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, People’s Republic of China;2. Computational and Theoretical Chemistry Group (CATCO), Department of Chemistry, Southern Methodist University, Dallas, TX, USA |
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Abstract: | ABSTRACTIt is essential to understand the intrinsic stability of the gold-thiolate clusters, which present extensive potential applications in many fields such as the catalysis, biomedicines and molecular machines. The electronic structures and aromaticity indexes of a series of Aum(SH)n (m, n?=?5–12) were comprehensively investigated through energetic, vibrational, magnetic, and electronic density properties, which are highly sensitive to the size and topological structure of the cluster. Generally, computational results of energy gap between the frontier molecular orbitals, normalized atomization energy (NAE), and electron localization function (ELF)-σ values exhibit the odd-even effect, in which clusters with the even number of free valence electrons, being reflected by the value of (m–n), possess relatively higher stability than the odd one. However, it is difficult to describe the stability of cluster with the sophisticated three-dimensional structure through one single aromaticity index such as the nucleus-independent chemical shift (NICS) value. Principal component analysis and clustering analysis of the calculation results of Aum(SR)n clusters suggest that the value of (m–n) and the Au4 unit are important for predicting the stability of the Au clusters. |
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Keywords: | Gold-thiolate clusters bond strength order principal component analysis clustering analysis |
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