STM study of oligo(phenylene-ethynylene)s. (27th May 2015)

• Record Type: Journal Article
• Authors: Thiele, Cornelius; Gerhard, Lukas; Eaton, Thomas R; Torres, David Muñoz; Mayor, Marcel; Wulfhekel, Wulf; Löhneysen, Hilbert v; Lukas, Maya
• Is Part Of: New journal of physics. Volume 17:Number 5(2015:May)
• Publication Date: 2015-05-27
• Subjects: molecular wire -- scanning tunneling microscopy -- molecular resolution -- single molecule conductance; Physics -- Periodicals; Physics; Periodicals; 530.05
• DOI: 10.1088/1367-2630/17/5/053043
• Languages: English
• ISSNs: 1367-2630

Abstract

Abstract: A detailed scanning tunneling microscopy (STM) study of two variants of oligo(phenylene ethynylene) (OPE) molecules is presented. These molecules might serve as molecular wires up to ≈ 5 nm in length. Self-assembled arrangements as well as single molecules on a Au(111) surface were analyzed. The molecular orbitals were directly imaged and are compared to density functional theory calculations. Sub-molecular resolution images of both molecules directly display the chemical structure. One of the OPE variants was lifted off the surface by the STM tip to measure the single-molecule conductance in order to explain previously reported low conduction values. Furthermore, we present a detailed analysis of a tip-induced conformational switching of the hexyl side groups from all-trans to a nonlinear conformation, which was observed for both variants.