Spectrofluorometric Studies VII. The Effect of Vibrational Quenchers on the Photochemistry of o‐Difluorobenzene

Abstract

The photochemistry of o‐difluorobenzene (o‐DFB) has been reexamined with narrower exciting bandwidths at 2490, 2540, 2580, 2660 and 2700 Å. The data indicate that the fluorescent yields are nearly the same as those reported previously. The effect of CO2 and CHCI3 on the singlet and triplet yields of o‐DFB excited at these wavelengths has also been studied. CO2, and CHCI3 do not have any effect on the fluorescent yield of o‐DFB excited at any wavelengths greater than 2490 Å. At 2490 Å, however, addition of CO2, or CHCI3, increases the fluorescent yield. Addition of CO2 or CHCI3 increases the triplet yield of o‐DFB at every exciting wavelength examined. Results of some studies on the intramolecular isomerization of o‐DFB at 2537 Å are also reported.