Direct Functionalization of the Hydroxyl Group of the 6-Mercapto-1-hexanol (MCH) Ligand Attached to Gold Nanoclusters

Au-MCH nanoclusters of (1.5 +/- 0.3) nm diameter (MCH = 6-mercapto-1-hexanol, HS-(CH2)6-OH) have been prepared and characterized by Transmission Electron Microscopy (TEM), UV-visible, Nuclear Magnetic Resonance (NMR), Fourier Transform Infrared (FTIR) absorption spectroscopies, X-ray Powder Diffraction (XRD), and Thermogravimetric Analysis (TGA). While in nanocluster form dispersed in solution, the OH terminal group of the MCH ligand has been directly functionalized through small organic molecule reactions in near-quantitative yield (>90%) to generate ester, carbamate, carboxylic acid, nitrite, and aldehyde groups, as recorded by FTIR spectroscopy. The size of the final gold nanocluster derivative is preserved for all the reactions studied here.