SYNTHESIS AND CHARACTERIZATION OF SELF-ASSEMBLED MONOLAYERS OF ALKYLATED 1-THIAHEXA(ETHYLENE OXIDE) COMPOUNDS ON GOLD

Self-assembled monolayers (SAMs) of a series of novel linear thiols co ntaining a 1-thiahexa(ethylene oxide) (THEO) moiety, i.e., HS(CH2CH2O) (6)R, where R = C10H21, C10D21, C18H37, and C18D37, were prepared on p olycrystalline gold (Au) and characterized by reflection absorption in frared spectroscopy (RAIRS), spectroscopic ellipsometry, surface plasm on resonance (SPR), and contact angle measurements. The SAMs are hydro phobic with contact angles, theta(a) (H2O), of 108 degrees-109 degrees for all surfaces. For all compounds, our data provide evidence for we ll-ordered monolayers in which the THEO moiety is arranged in a 7/2 he lix oriented normal to the substrate. The alkyl group conformation and tilt are similar to the corresponding n-alkanethiol SAMs.