1. Trapping of Charged Gold Adatoms by Dimethyl Sulfoxide on a Gold Surface
- Author
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Simone Velari, Maria Peressi, Erik Vesselli, Carlo Dri, Albano Cossaro, Giovanni Comelli, Zhijing Feng, Carla Castellarin-Cudia, Alberto Verdini, Alessandro De Vita, Feng, Zhijing, Velari, Simone, Cossaro, Albano, Castellarin Cudia, Carla, Verdini, Alberto, Vesselli, Erik, Dri, Carlo, Peressi, Maria, DE VITA, Alessandro, and Comelli, Giovanni
- Subjects
Photoemission spectroscopy ,Stereochemistry ,dimethyl sulfoxide ,General Physics and Astronomy ,Ionic bonding ,law.invention ,Metal ,Physics and Astronomy (all) ,Engineering (all) ,law ,Molecule ,General Materials Science ,DMSO ,density functional theory ,photoemission spectroscopy ,Chemistry ,Chemical polarity ,General Engineering ,gold ,adatom ,scanning tunneling microscopy ,Materials Science (all) ,Solvent ,Crystallography ,visual_art ,visual_art.visual_art_medium ,Density functional theory ,Scanning tunneling microscope - Abstract
We report the formation of dimethyl sulfoxide (DMSO) molecular complexes on Au(111) enabled by native gold adatoms unusually linking the molecules via a bonding of ionic nature, yielding a mutual stabilization between molecules and adatom(s). DMSO is a widely used polar, aprotic solvent whose interaction with metal surfaces is not fully understood. By combining X-ray photoelectron spectroscopy, low temperature scanning tunneling microscopy, and density functional theory (DFT) calculations, we show that DMSO molecules form complexes made by up to four molecules arranged with adjacent oxygen terminations. DFT calculations reveal that most of the observed structures are accurately reproduced if, and only if, the negatively charged oxygen terminations are linked by one or two positively charged Au adatoms. A similar behavior was previously observed only in nonstoichiometric organic salt layers, fabricated using linkage alkali atoms and strongly electronegative molecules. These findings suggest a motif for anchoring organic adlayers of polar molecules on metal substrates and also provide nanoscale insight into the interaction of DMSO with gold.
- Published
- 2015