The 275-nm absorption system of anisole

The 275-nm absorption systems of anisole (methoxybenzene) and three deuterated derivatives have been photographed at medium to high resolution. The origin bands lie at 36 386.4, 36 389.6, 36 557.2, and 36 560.4 cm^?1 for C₆H₅OCH₃, C₆H₅OCD₃, C₆D₅OCH₃, and C₆D₅OCD₃. The vibrational structure, which was analyzed in some detail, was found to be very similar to that of the analogous system of phenol. The spectrum consists of both allowed and forbidden components although the forbidden component, principally evident through activity of vibrations 18b and 6b, is relatively weak.