Resonance Raman spectra of carbonium ions adsorbed on porous Vycor glass

Abstract

Measurements of Raman spectra for unstable intermediates adsorbed on porous Vycor glass (PVG) have been made. When 1,1-diphenylethylene (DPE) was adsorbed on PVG, some unstable intermediates, blue, green and yellow species, were produced. Resonance Raman spectra of the green and yellow samples were obtained. The green species showed three new bands at 2975, 2930 and 2873 cm^–1 and the yellow species one at 2930 cm^–1. The observed Raman spectra confirm the existence of two kinds of carbonium ions. The structure of the carbonium ions and the formation mechanism of the intermediates were considered. Applicability of this technique to the study of small quantities of surface species is discussed.