Quantized double layer charging of Au130(SR)50 nanomolecules.

Quantized double layer (QDL) charging of a Au130(SR)50 nanomolecule is reported for the first time. In the past, QDL charging was known only for Au144(SR)60 and Au225(SR)75 nanomolecules, which intrigued much research in this field. Here, using differential pulse voltammetry, we demonstrate that Au130 shows QDL charging. Furthermore, 13 different oxidation-reduction waves corresponding to single electron charging events with a clear electrochemical gap of ∼ 450 mV are reported. For Au130(SR)50, both the QDL behaviour and electrochemical gap were observed. Considering the charging energy, the HOMO-LUMO gap of the nanomolecule is 200 mV. Further data analysis was performed to find the capacitance of Au130(SR)50. A comprehensive comparison with other magic sized nanomolecules was made to confirm the molecule-like to bulk metal transition with increasing size of gold nanomolecules. Gold nanomolecules with these electrochemical properties are of great interest in the field of catalysis.