Chemical bond formation showing a transition from physisorption to chemisorption

Huber, Ferdinand; Berwanger, Julian; Polesya, Svitlana; Mankovsky, Sergiy; Ebert, Hubert und Giessibl, Franz J. (2019): Chemical bond formation showing a transition from physisorption to chemisorption. In: Science, Bd. 366, Nr. 6462

Abstract

Surface molecules can transition from physisorption through weak van der Waals forces to a strongly bound chemisorption state by overcoming an energy barrier. We show that a carbon monoxide (CO) molecule adsorbed to the tip of an atomic force microscope enables a controlled observation of bond formation, including its potential transition from physisorption to chemisorption. During imaging of copper (Cu) and iron (Fe) adatoms on a Cu(111) surface, the CO was not chemically inert but transited through a physisorbed local energy minimum into a chemisorbed global minimum, and an energy barrier was seen for the Fe adatom. Density functional theory reveals that the transition occurs through a hybridization of the electronic states of the CO molecule mainly with s-, p(z)-, and d(z)(2)-type states of the Fe and Cu adatoms, leading to chemical bonding.

• Dokumententyp: Zeitschriftenartikel
• Fakultät: Chemie und Pharmazie > Department Chemie
• Themengebiete: 500 Naturwissenschaften und Mathematik > 540 Chemie
• ISSN: 0036-8075
• Sprache: Englisch