A New Band System Probably due to a Molecule CP

Abstract

WHEN investigating the band spectra of phosphorus I tried a discharge in a mixture of argon and phosphorus vapour. This discharge, with suitable arrangements of the concentrations of the two gases, shows an intense and extended band system in the wave-length region λ4000-λ2900 A. which does not occur in pure phosphorus vapour. So far as I am aware it has not hitherto been recorded. At the same time the Swan bands of the C₂ molecule are very intense in the visible region, obviously due to tap grease and sealing wax. As in a mixture of argon and a small trace of nitrogen, under the same conditions of discharge, the CN bands are specially strong (the C₂ bands of course also being present), it seems very probable that the new band system is due to a molecule CP which would be the analogue of CN. So far as I know, such a molecule, or a molecule (GP)₂ which would be analogous to (CN)₂, has not been found chemically. If the above conclusion that the new band system is due to CP is correct, it might be possible also to get chemical evidence of some simple CP compound. In order to obtain a further test of the above conclusion, an attempt is being made to get exposures strong enough to show the bands due to the isotope molecule C¹³P which would make possible a definite identification of the emitter of the bands in question.