Atomic structures of benzene and pyridine on Si(5 5 12)-2 x 1.
The adsorption structures of benzene and pyridine on Si(5 5 12)-2 x 1 were studied at 80 K by using a low-temperature scanning tunneling microscope and density functional theory calculations. These structures are different from those observed on low-index Si surfaces: benzene molecules exclusively bind to two adatoms, that is, with di-sigma bonds between carbon atoms and silicon adatoms, leading to the loss of benzene aromaticity; in contrast, pyridine molecules interact with adatom(s) through either Si-N dative bonding or di-sigma bonds. Dative bonding configurations with pyridine aromaticity are the dominant adsorption features and are more stable than di-sigma bonding configurations. Thus the dative bonding of nitrogen-containing heteroaromatic molecules provides a strategy for the controlled attachment of aromatic molecules to high-index surfaces.
Jeong
Hojin
H
Department of Physics, Chonbuk National University, Jeonju 561-756, Korea.
Jeong
Sukmin
S
Jang
S H
SH
Seo
J M
JM
Hahn
J R
JR
D000327:Adsorption; D001554:Benzene / Q000737:chemistry*; D016252:Microscopy, Scanning Tunneling; D008956:Models, Chemical; D015394:Molecular Structure; D011725:Pyridines / Q000737:chemistry*; D012680:Sensitivity and Specificity; D012825:Silicon / Q000737:chemistry*; D013499:Surface Properties; D013696:Temperature
D011725:Pyridines; D001554:Benzene; C023666:pyridine; D012825:Silicon