VIBRATIONAL EFFECTS IN XYLENES

An increase in pressure of inert gas enhances the fluorescences of the xylenes when exposed to radiation of shorter wavelengths than the 0,0 bands. At longer wavelengths the reverse effect is noted. An increase in temperature causes a decrease in fluorescence. Quantum yields of isomerization of xylenes to each other are wavelength dependent and are very small near the 0,0 band. These yields increase slightly with increase in temperature. 1,3-Pentadiene effectively quenches the singlet states of the xylenes. A mechanism can be advanced which correlates these various facts. © 1969, American Chemical Society. All rights reserved.