In a previous paper it was shown that a considerable number of lines attributed to singly-ionised carbon (C
+
or C II) could be arranged in a regular system of doublet series, involving transitions of a single electron. Numerous lines which appeared to belong to C II remained unclassified, but further analysis of the spectrum has been greatly facilitated by subsequent theoretical developments. In accordance with Hund’s theory, quartet as well as doublet terms are to be expected, and several of these additional terms have now been identified. The present communication gives an account of the newly classified lines, and includes improved measurements for some of the lines previously considered.
Observational Data
. The wave-lengths of most of the additional lines involved in the present discussion were determined in the course of the investigation of the doublet system. The sources included the spark between graphite poles in air, the spark in hydrogen, the arc
in vacuo
, and vacuum tubes of carbon dioxide. In the spark at atmospheric pressure, most of the lines are too diffuse for accurate measurement and wave-lengths were consequently determined chiefly from vacuum tubes. The vacuum tube spectra of oxygen under similar varied conditions served for the elimination of lines due to oxygen in the CO
2
spectra.
Organometallic Chemistry for Enabling Carbon Dioxide Utilization
