S. Joo, and Sang Woo Han, K. Kim
Jun 10, 2000
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0
Influential Citations
46
Citations
Journal
Journal of Physical Chemistry B
Abstract
The adsorption behavior of 1,3-propanedithiol (1,3-PDT) on a colloidal gold surface has been investigated by means of surface-enhanced Raman scattering (SERS). 1,3-PDT chemisorbed dissociatively on gold as a monothiolate. Moreover, we could clearly identify the S−S stretching band that reveals the formation of multilayers of 1,3-PDT on the colloidal gold surface. As for the case of 1,2-ethanedithiol, the intermolecular disulfide bond appeared to form even at a submonolayer coverage limit, implying that the adsorption of α,ω-alkanedithiol on gold does not take place homogeneously from the early stages of self-assembly. On the other hand, referring to the ab initio calculated vibrational frequencies of AuSCH2CH2CH2Cl, we could also analyze the concentration-dependent SER spectral features of 1,3-PDT in terms of the conformational isomerism around the two C−S bonds. Upon the increase of the bulk concentration of 1,3-PDT, a transition from a GG to GT conformation appeared to occur on the sol surface near the ...