Resonance Raman spectra of reaction intermediates formed from 1,1‐ diphenylethylene adsorbed on porous vycor glass and on a catalyst

Abstract

AbstractResonance Raman spectra of three types of reaction intermediates, blue, green and yellow species, formed from 1,1‐diphenylethylene adsorbed on porous Vycor glass were measured by means of an improved experimental technique and with suitable excitations. The blue species, which is the least stable intermediate, is found to be a cation radical, , and the characteristic Raman bands of and 2 stretching vibrations are clearly observed. For the green and yellow species more detailed spectra were obtained than in previous experiments. The coverages of the three intermediates are θ≈︂10−3 for each, being in agreement with the values expected from the numbers of Lewis and Brönsted acid sites on porous Vycor glass. Resonance Raman spectrum of the blue species on silica‐alumina, a catalyst, was also obtained by using the rotating sample technique.