Optical Characterization of Oligo (phenylene-ethynylene) Self-Assembled Monolayers on GoldMonolayers on Gold

Published

July 27, 2004

Author(s)

Lee J. Richter, Clayton S. Yang, P T. Wilson, Christina A. Hacker, Roger D. van Zee, J J. Stapleton, D L. Allara, Yuxing Yao, J M. Tour

Abstract

Vibrationally resonant sum frequency generation (VR-SFG) and spectroscopic ellipsometry (SE) have been used to characterize self-assembled monolayer films of unsubstituted and mononitro substituted oligo(phenylene-ethynylene) molecules on vapor deposited Au substrates. When combined with quantum chemical calculations of the relevant transition moment directions, orientation distributions and electronic excitation spectra are obtained. The orientation distribution from VR-SFG is in good agreement with previous IR reflection studies, indicating both molecules are tilted from the surface normal by about 30. The calculated resonant hyperpolarizabilities are in good agreement with experimental spectra. The optical polarizability extracted from SE suggests strong intermolecular interactions, consistent with molecular exciton theory.

Citation

Journal of Physical Chemistry B

Volume

108

Issue

33

Pub Type

Journals

Keywords

molecular electronics, monolayers on gold, spectroscopic ellipsometry, sum frequency generation

Citation

Richter, L. , Yang, C. , Wilson, P. , Hacker, C. , van, R. , Stapleton, J. , Allara, D. , Yao, Y. and Tour, J. (2004), Optical Characterization of Oligo (phenylene-ethynylene) Self-Assembled Monolayers on GoldMonolayers on Gold, Journal of Physical Chemistry B (Accessed November 22, 2024)