Density functional theory investigation of p-aminothiophenol molecules adsorbed on gold nanoparticles

Abstract

The current investigation is focused on quantum-chemical calculation and modelling of the SERS spectra for p-aminothiophenol molecules on gold nanoparticles. The DFT calculations are undertaken for p-aminothiophenol with S-H groups replaced by an S-Au bond. This model allows for more appropriate vibrational modes, electronic levels and transition moments description of the adsorbed p-aminothiophenol. Strong S-Au covalent bonding is indicated by the large concentration of electron density between S and bonded Au atoms and by distinctly directional Au-S-C bond whose bond angle is 105°.