Use of Solvents containing Ethyl Iodide in the Investigation of Phosphorescence Spectra of Organic Compounds

Abstract

M. KASHA1 has suggested that the yellow colour produced when α-chloronaphthalene and ethyl iodide are mixed is due to the enhancement of the lowest singlet–triplet absorption band of the naphthalene molecule. He interpreted this effect in terms of a collisional perturbation of spin-orbital coupling in the aromatic molecule, by the heavy iodine atom. The singlet–triplet absorption bands reported for benzene by a number of workers2 as well as those for a wide number of other aromatic molecules have been shown by Evans3 to be due to spin orbit perturbation by the inhomogeneous fields of dissolved paramagnetic oxygen molecules. The perturbing effects of ferric and cupric acetonyl acetonates have also been demonstrated4.