Au103(SR)45, Au104(SR)45, Au104(SR)46 and Au105(SR)46 nanoclusters

Abstract

High resolution ESI mass spectrometry of the “22 kDa” nanocluster reveals the presence of a mixture containing Au₁₀₃(SR)₄₅, Au₁₀₄(SR)₄₅, Au₁₀₄(SR)₄₆, and Au₁₀₅(SR)₄₆ nanoclusters, where R = –CH₂CH₂Ph. MALDI TOF MS data confirm the purity of the sample and a UV-vis spectrum shows minor features. Au₁₀₂(SC₆H₅COOH)₄₄, whose XRD crystal structure was recently reported, is not observed. This is due to ligand effects, because the 102 : 44 composition is produced using aromatic ligands. However, the 103-, 104- and 105-atom nanoclusters, protected by –SCH₂CH₂Ph and –SC₆H₁₃ ligands, are at or near 58 electron shell closing.