Dresden 2006 – wissenschaftliches Programm
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CPP: Chemische Physik und Polymerphysik
CPP 12: POSTER Colloids, Nanoparticles and Self-Organizing Systems
CPP 12.15: Poster
Dienstag, 28. März 2006, 17:00–19:00, P3
Analysis of Self Assembled Monolayers (SAMs) on metallic substrates by — •P. Angelova1, M. Gensch2, K. Hinrichs2, K. Kostova1, and D. Tsankov1 — 1Institute of Organic Chemistry, Bulgarian Academy of Sciences, Acad. G. Bonchev Str. Bl. 9, 1113 Sofia, Bulgaria — 2ISAS-Institute for Analytical Sciences, Department Berlin, Albert Einstein Str. 9, 12489 Berlin, Germany
Long-chain alkanethiols and disulfides tend to adsorb onto metallic surfaces and to form closely packed and well ordered monomolecular films. Besides adsorption, the self-assembly also includes spontaneous self-organization of the molecules constituting the film, mostly by means of van der Waals interactions. Essential role in forming highly ordered films has the type of the molecules which affects the intermolecular distance and the degree of orientation. Newly synthesized para-substituted benzyl esters of 16-mercaptohexadecanoic acid, containing NO2, CN, OCH3 and Cl as substituents were prepared as SAMs on different metallic substrates (Au, Ag, Pd) and investigated by IR ellipsometry. The specific stretching vibrations of the indicator groups were used for identifying of the film orientation. Particularly useful were the stretching vibrations of the NO2 group and the respective optical simulations are presented. As input data for the simulations served vibrational parameter derived from previuosly investigated Langmuir-Blodgett films. The determination of thickness and dependence of the ellipsometric spectra on the average orientation of the vibrational transition moments of the NO2 groups in the films with aligned molecules is addressed.