Photoacoustic spectra of isometric amino and hydroxy pyridines

Abstract The photoacoustic spectra of isomeric aminopyridines and isomeric hydroxypyridines in the UV-visible region have been recorded in the powder form. These spectra have been analysed in the light of liquid phase absorption spectra. The relative intensities in the photoacoustic spectra have been interpreted in terms of the nonradiative transitions. A possible ordering of the singlet states arising from n →π* and π →π* electron promotions has also been suggested.