Longest wavelength [formula omitted] electronic absorption spectra of o- and m-tolualdehydes

Abstract

The long-wavelength absorption spectra ( π ← π ∗ systems) of o- and m-tolualdehydes have been photographed on a Zeiss Q-24 medium quartz spectrograph in the vapor phase. In o-tolualdehyde 30 red degraded bands have been recorded in the region 2730–2975 Å and the strong band at 2918.8 Å has been taken as the (0-0) band. In m-tolualdehyde 48 red degraded bands have been observed in the region 2447–2980 Å and the strong band at 2914.0 Å has been taken as the (0-0) band. The spectra have been analyzed in terms of six ground-state frequencies (175, 255, 410, 530, 560, and 630 cm −1) and nine excited state frequencies (170, 245, 345, 375, 620, 700, 990, 1090, and 1195 cm −1) in o-derivative and seven ground-state frequencies (125, 195, 340, 445, 516, 655, and 740 cm −1) and thirteen excited state frequencies (105, 180, 320, 412, 490, 605, 725, 800, 955, 1050, 1155, 1260, and 1570 cm −1) in the case of m-derivative.