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Rayleigh relaxation of pyrazine, pyridine and piperidine molecules adsorbed on the roughened Ag electrode by light beating technique
Author(s) -
Wu GuoZhen
Publication year - 1991
Publication title -
chinese journal of chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.28
H-Index - 41
eISSN - 1614-7065
pISSN - 1001-604X
DOI - 10.1002/cjoc.19910090105
Subject(s) - piperidine , chemistry , pyrazine , pyridine , rayleigh scattering , electrode , relaxation (psychology) , molecule , raman scattering , analytical chemistry (journal) , raman spectroscopy , organic chemistry , optics , psychology , social psychology , physics
The light beating technique (intensity correlation algorithm) was employed to analyze the Rayleigh scattering from the roughened Ag electrode in very dilute (10 −4 M) pyrazine, pyridine and piperidine aqueous solutions containing KC1 (0.1 M). The relaxation time is longer when the applied voltages are between −0.4 V and −0.8 V (vs. SCE) where the Raman effect also shows greater surface enhancement. Also observed was that for the piperidine case the relaxation time reaches its maximum at the more negative applied voltage. The origin of the relaxation is attributed mainly to the desorption process of the pyrazine, pyridine and piperidine molecules off the roughened Ag electrode. An electrostatic model was also proposed for the interpretation of these experimental observations.