The electronic emission and absorption spectra of o-fluorobenzaldehyde have been studied. The emission spectrum recorded on a Fuess glass and a medium quartz spectrograph lies in the region 26 668–17 862 cm−1 and the absorption spectrum recorded on a Zeiss Q–24 medium quartz spectrograph lies in the region 30 995–24 610 cm−1. The O-O band has been observed at 26 337 cm−1. The C=O stretching frequency 1733 cm−1 in the ground state and 1355 cm−1 in the excited state is most intense and forms progressions of bands both in the emission and absorption spectra. The observed bands have been interpreted as combinations of the C=O stretching frequency and its multiples with other fundamentals. The transition involved is A'–A" (n-π*).
M. P. Srivastava and I. S. Singh, "n-π* Electronic Emission and Absorption Spectra of o-Fluorobenzaldehyde in Vapor Phase," Appl. Spectrosc. 24, 36-41 (1970)