Some new bands of CCl are recorded and these together with those reported by earlier workers are arranged in a vibrational scheme. The electronic transition is ${}_{}{}^2{}_{}{}^{}\Sigma \to {}_{}{}^2{}_{}{}^{}\Pi$, the doublet separation for the ${}_{}{}^2{}_{}{}^{}\mathrm{II}$ state being 138 ${\mathrm{cm}}^{-1\mathrm{}}$. By way of comparison it is mentioned that the uncondensed transformer discharge gave C${\mathrm{F}}_2$ bands in the case of C${\mathrm{F}}_4$, CCl, and ${\mathrm{Cl}}_2$ bands in the case of C${\mathrm{Cl}}_4$ and only ${\mathrm{Br}}_2$ bands in C${\mathrm{Br}}_4$. It is pointed out that the supposed CBr bands reported by Durie and Iredale are not due to CBr but due to ${\mathrm{Br}}_2$.

• Received 7 September 1949

DOI:https://doi.org/10.1103/PhysRev.77.79