UV/Vis spectroelectrochemical evidence of rectification of quantized charging in monolayer-protected gold cluster films

The spectral corroboration of ion-induced rectification of quantized charging of C6-Au monolayer-protected clusters (MPC) films in aqueous solutions was presented. The suitable film preparation conditions and careful spectroelectrochemical cell design enabled us to detect band evolution in the UV/Vis absorption spectra concurrent with each single anodic charging steo and suppression of spectroelectrochemical signal in the negative potential region. The potential-induced spectral changes were linearly dependent on the MPC core charge and evidenced film stability and reversibility of the discrete electronic transitions. C-6 Au MPCs were synthesized according to the two-phase Brust method.