Chemisorption of Acetophenone on Si(111)-7 x 7. Polar Aromatic Molecule on Electronically Complex Surface
2016
Abstract
Temperature-dependent chemisorption of acetophenone molecules on the Si(111)-7 X 7 reconstruction was studied by means of scanning tunneling microscopy, scanning tunneling spectroscopy, and density functional theory calculations. A configuration interpreted as a silyl enolether has been repeatedly observed on the surface at room temperature and after annealing to 75 degrees C.
The most frequent structure on the surface stable up to 150 degrees C is identified as a 1,6-adduct to two adatoms of the neighboring half unit cells. The results suggest that presence of the polar group in the molecule affects the chemisorption in a way that leads to bonding with two adatoms.