Nishino, T.; Buhlmann, P.; Ito, T.; Umezawa, Y. Phys. Chem. Chem. Phys. 2001, 3, 1867
Abstract
Gold tips modified with self-assembled monolayers were used for the scanning tunneling microscopy (STM) observation of monolayers of dihexadecyl ether and 1,11-bis(hexadecyloxy)undecane physisorbed onto highly ordered pyrolytic graphite. The ether oxygens gave dark lines in STM images measured with unmodied and thiophenol-modied tips. In contrast, they appeared as bright lines in images observed with tips modified with 4-mercaptobenzoic acid, allowing the selective recognition of ether oxygens. These changes in image contrasts for ether oxygens appear to result from the facilitation of electron tunneling by hydrogen bond interactions.