Emission spectra of 3,4- and 3,5-difluorobenzaldehyde vapors: Conformer-specific phosphorescence from the 3,4-derivative

Emission and absorption spectra of 2,3,4-, 2,3,5- and 2,4,5-trifluorobenzaldehyde vapors

“…Although aromatic carbonyl compounds such as acetophenone and benzophenone are known to exhibit phosphorescence in the static vapor phase, the observed emission spectra are broad at temperatures in the neighborhood of room temperature [1]. On the other hand, aromatic carbonyl compounds such as benzaldehyde and fluorobenzaldehydes are known to exhibit comparatively sharp emission bands in the vapor phase [1][2][3][4][5].…”

“…We have recently shown for mono-and di-substituted fluorobenzaldehydes that the rotational isomers are separable through the phosphorescence spectral measurements and determined the energy levels of the two rotational isomers for 3-fluorobenzaldehyde and 3,4-difluorobenzaldehyde vapors in the ground and first triplet excited states by means of emission and infrared spectroscopy [2][3][4][5]. However, at present no information is available for the emission and absorption spectral data of trifluorobenzaldehyde vapors.…”