Structure and Chemical Characterization of Self-Assembled Mono-Fluoro-Substituted Oligo(phenylene-ethynlyene) Monolayers on Gold

Published

June 22, 2004

Author(s)

Christina Hacker, James D. Batteas, J C. Garno, Manuel Marquez, Curt A. Richter, Lee J. Richter, Roger D. van Zee, Christopher D. Zangmeister

Abstract

Monolayers of oligo(phenylene-ethynylene) (OPE) molecules have exhibited promise in molecular electronic test structures. This paper discusses films formed from novel molecules within this class, 2-fluoro-4-phenylethynyl-1-[(4-acetylthio)-phenylethynyl]benzene (F-OPE). The conditions of self-assembled monolayer (SAM) formation were systematically altered to fabricate reproducible high-quality molecular monolayers from the acetate-protected F-OPE molecule. Detailed characterization of the F-OPE monolayers was performed by using an array of surface probes, including reflection absorbance infrared spectroscopy (RAIRS), contact angle measurements (CA), spectroscopic ellipsometry (SE), X-ray photoelectron spectroscopy (XPS), ultraviolet photoemission spectroscopy (UPS), and atomic force microscopy (AFM). The SAM formed without removal of the F-substituent and without oxidation of the thiol, as determined from XPS and RAIRS. The monolayer thickness, determined from SE and AFM based nanolithography, was consistent with the formation of a densely packed monolayer. The valence electronic structure of the SAM was consistent with an aromatic structure shifted by the electron-withdrawing fluorine substituent.

Citation

Langmuir

Volume

20

Issue

15

Pub Type

Journals

Citation

Hacker, C. , Batteas, J. , Garno, J. , Marquez, M. , Richter, C. , Richter, L. , van Zee, R. and Zangmeister, C. (2004), Structure and Chemical Characterization of Self-Assembled Mono-Fluoro-Substituted Oligo(phenylene-ethynlyene) Monolayers on Gold, Langmuir (Accessed April 26, 2024)