Knowledge Bank

The triplet-singlet emission spectra of toluene, ethyl-benzene, n-propylbenzene, and n-butylbenzene were studied at several concentrations in a rigid solution (EPA) and in the crystalline state at liquid nitrogen and liquid helium temperatures. A comparison of the vibrational analyses of these spectra was made with the analysis of the tolune spectrum given by Dikun and Sveshnikov. The crystalline spectra of these compounds were shifted to the red and found to have a different vibrational structure from that of the solution spectra. Special bearing of concentration effects on the interpretation of the spectra will be discussed.