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O: Oberflächenphysik
O 2: Organische Dünnschichten I
O 2.4: Vortrag
Freitag, 4. März 2005, 11:30–11:45, TU EB301
Aliphatic selenolates on gold and silver substrates — •Andrey Shaporenko1, Avi Ulman2, Andreas Terfort3 und Michael Zharnikov1 — 1Angewandte Physikalische Chemie, Universität Heidelberg, Im Neuenheimer Feld 253, 69120 Heidelberg, Germany — 2Department of Chemical Engineering, Polytechnic University, Brooklyn 11201, New York, USA — 3Anorganische und Angewandte Chemie, Universität Hamburg, 20146 Hamburg, Germany
We studied self-assembled monolayers (SAMs) formed from didodecyl diselenide (C12SeSeC12) and didodecyl selenide (C12SeC12) on (111) Au and Ag substrates. C12SeSeC12 was found to form contamination-free, densely-packed, and well-ordered C12Se SAMs on both substrates, whereas the adsorption of C12SeC12 occurred only on Au and resulted in the formation of a SAM-like C12SeC12 film with a low packing density and a conformational disorder. The properties of the C12Se SAMs were compared with those of dodecanethiolate (C12S) SAMs. The packing density, orientational order, and molecular inclination in C12Se/Au and C12S/Au were found to be very similar. In contrast, C12Se/Ag exhibited significantly lower packing density, a lower degree of the conformational and orientational order, and a larger molecular inclination than C12S/Ag. The results suggest a sp3 bonding configuration for the selenium atom on Au and Ag and indicate a larger corrugation of the headgroup-substrate binding energy surface in C12Se/Ag than in C12S/Ag.