Infrared-visible sum-frequency spectroscopic characterization of the molecular orientation of self-assembled monolayers of alkanethiols on obliquely deposited gold films

This paper reports on a detailed study that sought to establish an understanding of the molecular orientation of self-assembled monolayers (SAMs) formed from n-alkanethiols on obliquely deposited gold films. This study focuses on the azimuthal symmetry of the resonance signal obtained by rotation of the substrate about its normal. The important aspect of this work is to account for the anisotropic sum-frequency signal generated by gold and the preferred in- and out-of-plane orientations of the vibrational stretches.