Quenching of the Photoisomerization\nof Azobenzene\nSelf-Assembled Monolayers by the Metal Substrate

Abstract

In this study, we aim at investigating\nthe role played by the metal\nsurface as a possible dissipative channel in the photoisomerization\nprocess of azobenzene-derivative-based self-assembled monolayers (azo-SAMs).\nIn particular we compare the cases of gold and platinum. We study\nthe excitonic transfer <i>phenomena</i> of two azo-derivatives\n(both in <i>trans</i> and in <i>cis</i> conformation)\nchemisorbed on Au{111} and Pt{111} to the metal surfaces. The metal\neffects are evaluated within the local and nonlocal regimes, showing\nthat nonlocality in the metal response plays an important role and\nnonlocal accounting quenching rates are one order of magnitude smaller\nthan the corresponding local results. The couplings are stronger for\nAu{111} than for Pt{111}, but for both cases the energy transfer between\nthe molecule and the metal turns out not to be able to suppress photoisomerization.