title: Self-assembled monolayers of semifluorinated alkaneselenolates on noble metal substrates.
abstract: Self-assembled monolayers (SAMs) formed from semifluorinated dialkyldiselenol (CF(3)(CF(2))(5)(CH(2))(2)Se-)(2) (F6H2SeSeH2F6) on polycrystalline Au(111) and Ag(111) were characterized by high-resolution X-ray photoelectron spectroscopy, infrared reflection absorption spectroscopy, near edge X-ray absorption fine structure spectroscopy, scanning tunneling microscopy, and contact angle measurements. The Se-Se linkage of F6H2SeSeH2F6 was found to be cleaved upon the adsorption, followed by the formation of selenolate-metal bond. The resulting F6H2Se SAMs are well-ordered, densely packed, and contamination-free. The packing density of these films is governed by the bulky fluorocarbon part, which exhibits the expected helical conformation. A noncommensurate hexagonal arrangement of the F6H2Se molecules with an average nearest-neighbor spacing of about 5.8 +/- 0.2 A, close to the van der Waals diameter the fluorocarbon chain, was observed on Au(111). The orientation of the fluorocarbon chains in the F6H2Se SAMs does not depend on the substrate-the average tilt angle of these moieties was estimated to be about 21-22 degrees on both Au and Ag.
authors.affiliation: Angewandte Physikalische Chemie, Universität Heidelberg, Im Neuenheimer Feld 253, 69120 Heidelberg, Germany.
authors.forename: A
authors.initials: A
authors.lastname: Shaporenko
authors.forename: P
authors.initials: P
authors.lastname: Cyganik
authors.forename: M
authors.initials: M
authors.lastname: Buck
authors.forename: A
authors.initials: A
authors.lastname: Ulman
authors.forename: M
authors.initials: M
authors.lastname: Zharnikov