X-ray Photoelectron Spectroscopy and Near-Edge X-rayAbsorption Fine Structure Study of Water Adsorption onPyridine-Terminated Thiolate Self-Assembled Monolayers
Adsorption of water on self-assembled monolayers (SAMs) of 4-(4-mercaptophenyl)pyridine on gold atlow temperatures under ultrahigh vacuum conditions is studied by synchrotron radiation X-ray photoelectronand absorption spectroscopy. Water adsorption induces a strong modification of the chemical state of thepyridine N atoms at the SAM/ice interface, indicative for strong H bonding and partial proton transferbetween water molecules and pyridine moieties. Additionally, the initial molecular orientation within theSAM is changed upon formation of an adsorbed water multilayer.
