Surface anchoring and dynamics of thiolated azobenzene moleculeson Au(111)

摘要

We have investigated the temperature-dependent behavior of thiolated azobenzene molecules onAu(111) using scanning tunneling microscopy. The addition of a thiol functional group toazobenzene molecules leads to increased surface anchoring of single azobenzene molecules to gold.Thiolated azobenzene shows diverse surface morphology and does not form well-ordered structuresat low coverage. At elevated temperatures, anchored molecules are observed to spin in place viahindered rotation. By measuring the number of rotating molecules as a function of temperature andusing a simple model, we are able to estimate the energy barrier and attempt frequency for thermallyinduced hindered rotation to be 102 ± 3 meV and 110 ± 2 GHz, respectively.