Synthesis of selenolate-protected Au18(SeC6H5)14 nanoclusters

Abstract

This work reports the first synthesis of selenophenolate-protected Au₁₈(SePh)₁₄ nanoclusters. This cluster exhibits distinct differences from its thiolate analogue in terms of optical absorption properties. The Au₁₈(SePh)₁₄ nanoclusters were obtained via a controlled reaction of Au₂₅(SCH₂CH₂Ph)₁₈ with selenophenol. Electrospray ionization time-of-flight mass spectrometry (ESI-TOF-MS) revealed the crude product to contain predominantly Au₁₈(SePh)₁₄ nanoclusters, and side products include Au₁₅(SePh)₁₃, Au₁₉(SePh)₁₅ and Au₂₀(SePh)₁₆. High-performance liquid chromatography (HPLC) was employed to isolate Au₁₈(SePh)₁₄ nanoclusters. The results of thermogravimetric analysis (TGA), elemental analysis (EA), and ¹H/¹³C NMR spectroscopy confirmed the cluster composition. To the best of our knowledge, this is the first report of selenolate-protected Au₁₈ nanoclusters. Future theoretical and X-ray crystallographic work will reveal the geometric structure and the nature of selenolate-gold bonding in the nanocluster.