title: Compression-Induced Conformation and Orientation Changes in an n-Alkane Monolayer on a Au(111) Surface.
abstract: The influence of the preparation method and adsorbed amount of n-tetratetracontane (n-C44H90) on its orientation in a monolayer on the Au(111) surface is studied by near carbon K-edge X-ray absorption fine structure spectroscopy (C K-NEXAFS), scanning tunneling microscopy (STM) under ultrahigh vacuum, and infrared reflection-absorption spectroscopy (IRAS) at the electrochemical interface in sulfuric acid solution. The n-C44H90molecules form self-assembled lamellar structures with the chain axis parallel to the surface, as observed by STM. For small amounts adsorbed, the carbon plane is parallel to the surface (flat-on orientation). An increase in the adsorbed amount by ∼10-20% induces compression of the lamellar structure either along the lamellar axis or alkyl chain axis. The compressed molecular arrangement is observed by STM, and induced conformation and orientation changes are confirmed by in situ IRAS and C K-NEXAFS.
authors.affiliation: Department of Organic and Polymer Materials Chemistry, Faculty of Engineering, Tokyo University of Agriculture and Technology , Tokyo 184-8588, Japan.
authors.forename: Osamu
authors.identifier: 0000-0002-2206-4035
authors.initials: O
authors.lastname: Endo
authors.affiliation: Department of Applied Chemistry and Biotechnology, Faculty of Engineering, Chiba University , Chiba 263-8522, Japan.
authors.forename: Masashi
authors.identifier: 0000-0002-2986-1133
authors.initials: M
authors.lastname: Nakamura
authors.affiliation: Photon Factory, High Energy Accelerator Research Organization (KEK-PF), Institute of Materials Structure Science (IMSS) , Tsukuba 305-0801, Japan.
authors.forename: Kenta
authors.initials: K
authors.lastname: Amemiya
authors.affiliation: Department of Organic and Polymer Materials Chemistry, Faculty of Engineering, Tokyo University of Agriculture and Technology , Tokyo 184-8588, Japan.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Ozaki