Band spectrum of aluminium chloride (AlCl)

Abstract

In the course of experiments on the spectrum of hydrogen chloride, a strong band system having its greatest intensity about λ 2610 was observed when using discharge tubes with aluminium electrodes. It was found that these bands had previously been noted by Jevons as occurring in his experiments on silicon chloride in active nitrogen, and had subsequently been described and attributed by him to aluminium chloride. The photographs obtained by the authors, however, should this band system in far greater detail than those of Jevons, and as it obviously included a large number of bands associated with the heavier isotope of chlorine, it seemed desirable to investigate the structure of the spectrum more completely. For the more complete production of this band system, Jevons passed discharges through the vapour of aluminium chloride, AlCl 3 , and this method has been adopted in the present investigation. As obtained in this way, the band system extends from λ 2555 to about λ 2810 and exhibits features of considerable interest besides those due to the presence of isotopes.