The preserved aromaticity of aniline molecules adsorbed on a Si(5 5 12)-2x1 surface.
We present a scanning tunneling microscopy and first-principles calculations study of the adsorption structures of aniline on a Si(5 5 12)-2x1 surface. Dissociation from the aniline molecules of one or two H atom(s) bonded to N is favored, and then adsorption onto adatom, tetramer, and dimer rows of Si(5 5 12)-2x1 occurs in several distinct configurations. On the adatom row, aniline binds to an adatom in a tilted configuration, which is formed via a sigma bond between the adatom and N, with one dissociated H atom adsorbed on a nearby adatom. No further hydrogen dissociation occurs. On the tetramer and dimer rows, the structures with two dissociated hydrogens and upright configurations are the most stable. Aniline does not adsorb onto the honeycomb chains; this adsorption configuration has a low adsorption energy. In all the adsorption configurations of aniline on this surface, the molecule's aromaticity is preserved. Thus Si-N bonding of aromatic amine molecules provides a strategy for the homogeneous aromatic functionalization of high index Si surfaces.
Jang
Sang Hoon
SH
Department of Chemistry and Research Institute of Physics and Chemistry, Chonbuk National University, Jeonju 561-756, Republic of Korea.
Jeong
Sukmin
S
Hahn
Jae Ryang
JR
D000327:Adsorption; D000814:Aniline Compounds / Q000737:chemistry*; D003198:Computer Simulation; D016252:Microscopy, Scanning Tunneling; D008956:Models, Chemical; D008958:Models, Molecular; D012825:Silicon / Q000737:chemistry*; D013499:Surface Properties
D000814:Aniline Compounds; C023650:aniline; D012825:Silicon