title: Role of lateral alkyl chains in modulation of molecular structures on metal surfaces.
abstract: We use low energy electron diffraction, scanning tunneling microscopy, first-principles density-functional theory, and molecular mechanics calculations to analyze the adsorption and growth of quinacridone derivatives (QA) with alkyl chains of 4 and 16 carbon atoms on a Ag(110) substrate. Surprisingly, we find that the alkyl chains determine the orientation of the molecular overlayers. While the interaction of QA and the Ag substrate is primarily due to chemical bonding of oxygen to the silver substrate, determining the molecular orientation and preferred adsorption site, the intermolecular arrangement can be adjusted via the length of alkyl chains. We are thus able to fabricate uniform QA films with very well controlled physical properties.
authors.affiliation: Beijing National Laboratory of Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Post Office Box 603, Beijing 100080, China.
authors.forename: D X
authors.initials: DX
authors.lastname: Shi
authors.forename: W
authors.initials: W
authors.lastname: Ji
authors.forename: X
authors.initials: X
authors.lastname: Lin
authors.forename: X B
authors.initials: XB
authors.lastname: He
authors.forename: J C
authors.initials: JC
authors.lastname: Lian
authors.forename: L
authors.initials: L
authors.lastname: Gao
authors.forename: J M
authors.initials: JM
authors.lastname: Cai
authors.forename: H
authors.initials: H
authors.lastname: Lin
authors.forename: S X
authors.initials: SX
authors.lastname: Du
authors.forename: F
authors.initials: F
authors.lastname: Lin
authors.forename: C
authors.initials: C
authors.lastname: Seidel
authors.forename: L F
authors.initials: LF
authors.lastname: Chi
authors.forename: W A
authors.initials: WA
authors.lastname: Hofer
authors.forename: H
authors.initials: H
authors.lastname: Fuchs
authors.forename: H-J
authors.initials: HJ
authors.lastname: Gao