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

High resolution ESI mass spectrometry of the 22 kDa nanocluster reveals the presence of a mixture containing Au-103(SR)(45), Au-104(SR)(45), Au-104(SR)(46), and Au-105(SR)(46) nanoclusters, where R = -CH2CH2Ph. MALDI TOF MS data confirm the purity of the sample and a UV-vis spectrum shows minor features. Au-102(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.