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Author Sandhyarani, N. ♦ Skanth, G. ♦ Sheela, B. ♦ Yegnaraman, V. ♦ Pradeep, T.
Source CSIR-Central Electrochemical Research Institute
Content type Text
Publisher Elsevier
File Format PDF
Copyright Year ©1999
Language English
Subject Domain (in DDC) Natural sciences & mathematics ♦ Chemistry & allied sciences ♦ Technology ♦ Engineering & allied operations ♦ Applied physics
Subject Keyword Electrodics and Electrocatalysis
Abstract The monolayers of 2-mercaptobenzothiazole (MBT) on polycrystalline Au and Ag films have been studied by surface-enhanced Raman (SERS) and X-ray photoelectron (XPS) spectroscopies. Whereas MBT adsorbs with its molecular plane flat on Ag, its plane is perpendicular on Au. This difference in adsorbate geometry is manifested as differences in the intensities of certain vibrational peaks in the Raman spectra. Ab initio molecular orbital (MO) calculations suggest that MBT adsorbs on Au in the thione form and on Ag in the thiol form. The monolayers are stable up to a temperature of 473 K, much higher than most of the self-assembled monolayers (SAMs) studied so far. The adsorption geometry does not undergo any significant change when the monolayers are heated, although minor changes are observed in the SER spectra of the Ag monolayer. Raman intensities of all the bands increase with heating, and the enhanced intensity is preserved even after cooling. This is attributed to monolayer-induced coalescence of gold islands leading to the formation of an extended self-assembly. XPS studies confirm chemisorption, although structural details are not manifested.
Educational Use Research
Education Level UG and PG
Learning Resource Type Article
Publisher Date 1999-01-01
Journal PeerReviewed