Dissociation Energy of Carbon Monoxide

Abstract

A SUMMARY of the various recent views on the dissociation energy of carbon monoxide is given by Gaydon¹ in his "Dissociation Energies", in which he eliminates all proposed values except 11·11 and 9·85 eV., and finally accepts the former as being the more probable. At about the same time, Kenty, Aicher, Noel, Paritsky and Paolino² observed a new band system of molecular oxygen in a gas discharge containing carbon dioxide which suggested a lower limit for D (CO) of 9·4 eV. Since then, Hagstrum³ has defended his electron-impact value of 9·6 eV., Gëro⁴ through Valatin⁵ still retains faith in 6·9 eV., and Brewer, Gilles and Jenkins⁶ have made a determination of the heat of sublimation of graphite which indirectly supports 11·1 eV. Due to this confusion, which has now persisted for some time, the spectroscopic method of evaluating dissociation energies is in danger of being regarded with cynicism by those physical and organic chemists who urgently need this constant for carbon monoxide. The trouble lies in the lack of any dissociation continuum in the spectrum of carbon monoxide, and accordingly attention has been centred on predissociation phenomena, of which there seems no lack.