Investigation of the 3-(mercaptopropyl)trimethoxysilane-polycrystalline gold interface by underpotential deposition of cadmium (II), copper (II), lead (II), and thallium (I)

ANYL 59

Goyce A. Wolfe, goyce@email.arizona.edu, Clarissa L. Embach, clarissa@email.arizona.edu, and Jeanne E. Pemberton, pembertn@u.arizona.edu. Department of Chemistry, University of Arizona, 1306 East University Boulevard, Tucson, AZ 85721
Underpotential deposition of metals (UPD) is used to investigate the size of two-dimensional pores that are formed in cross-linked self-assembled monolayers of (3-mercaptopropyl)trimethoxysilane (3MPT) on polycrystalline gold. After hydrolysis of the methoxy groups and condensation of the resulting hydrolyzed terminal groups, an almost fully cross-linked, siloxane-bonded network is produced. This network has been previously proposed to be comprised of six-membered siloxane rings that should allow accessibility to the underlying gold surface for ions of the appropriate size. UPD studies on a series of metal cations of varying Stokes radii, including Cd2+, Cu2+, Pb2+ and Tl+, are used to estimate the pore size of these two-dimensional siloxane rings. Restricted mass transport through the siloxane rings is manifested in the cyclic voltammetric response of both the UPD reduction and stripping processes for cations with Stokes' radii that exceed the ring diameter.
 

General Papers
7:00 PM-9:00 PM, Sunday, 10 September 2006 Moscone Center -- Hall D, Poster

Division of Analytical Chemistry

The 232nd ACS National Meeting, San Francisco, CA, September 10-14, 2006