In the first part of the study, the deposition of copper on the Au(111) electrode in the presence and absence of thymine or adenine was studied with a series of cyclic voltammetry, chronocoulometry and XPS techniques. Cu-UPD in perchlorate proceeds extremely slow compared to that in specifically adsorbing sulphate anion. Interestingly, the physisorbed thymine molecules (in perchlorate) act as catalysts for the UPD of copper like sulphate anion, however, act as inhibitor kinetically for the bulk

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... deposition. Independent of the lateral interaction of thymine molecules at the Au(111) surface, the deposition process becomes faster depending on concentration of thymine. During the deposition of copper, thymine molecules reorientate and change their adsorption state from a physisorbed state on the blank Au(111) substrate to a chemisorbed one on top of the copper monolayer. Upon chemisorption, thymine molecules become deprotonated most likely via N(3) and some charge transfer from the deprotonated thymine molecules to copper adatoms takes place. The catalytical action of thymine molecules can be explained for energetical reasons. Due to the chemisorption of thymine molecules on top of the copper layer, the potentials of zero charge of Au(111) and copper become close together leading to a reduction of the surface strain between the two metals. Deposition as well as dissolution of copper in the absence and the presence of thymine obeys a nucleation and growth mechanism with time dependent supersaturation and undersaturation, respectively. In adenine containing electrolyte, the UPD of copper is supported at a low degree in early stages, however, at further stages adenine suppresses the UPD. The higher strength of the interaction between charge-transferred adenine complex and gold surface atoms leads to the inhibition. In the second part, the deposition of silver on Au(111) in the presence and absence of thymine was studied using CV, chronocoulometry, EC-STM and XPS techniques. In the absence of thymine, at higher underpoten [...]