Heterogeneous electron-transfer rate constant measurements on substituted ruthenium pentaammine pyridyl complexes: Evidence for pyridyl substituent placement effects on the degree of adiabaticity at alkanethiol-modified gold electrodes

ANYL 115

Huan-Ting Lin, curtisj@usfca.edu, Hu Min Hom, and Jeff C. Curtis, curtisj@usfca.edu. Department of Chemistry, University of San Francisco, 2130 Fulton Street, San Francisco, CA 94117
Kinetic evidence garnered perviously in our lab (stopped-flow and NMR linebroadening) has shown that the rates for bimolecular electron-transfer reactions between ruthenium pentaammine pyridyl complexes are enhanced in cases where the ligated pyridyl ring bears certain substituents in the 4-position. We report here on a set of electrode kinetics measurements on both bare gold and on alkanethiol-modified gold surfaces. The special reactivity of the 4-substituted pyridyl complexes is recovered on the thiol-modified electrodes, but it is only barely present if at all on bare gold. Implications with respect to electronic coupling will be discussed.
 

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