The Electronic Emission Spectrum ofC13O16

Abstract

That part of the emission spectrum of ${\mathrm{C}}^{13}$ ${\mathrm{O}}^{16}$ occurring between 1900 and 6500A has been obtained in an uncondensed discharge under conditions of low current density. A rotational analysis of the 0-1, 0-2, 0-3, 0-4, 0-5, and 1-1 Angstrom bands has been made. The molecular constants derived therefrom agree closely with those calculated for ${\mathrm{C}}^{13}$ ${\mathrm{O}}^{16}$ from spectroscopic data pertaining to ${\mathrm{C}}^{12}$ ${\mathrm{O}}^{16}$. The behavior, with respect to isotopic substitution, of the first vibrational quantum in the $B{}_{}{}^1{}_{}{}^{}\Sigma _{}^{+}{}_{}{}^{}$ electronic state suggests the possibility of rapid convergence of the levels. In the fourth positive group of ${\mathrm{C}}^{13}$ ${\mathrm{O}}^{16}$, thirty-five band heads have been measured, involving nine $v^{\prime \prime }$ progressions and twelve $v^{\prime }$ progressions, each including at least two measured bands. Band origins calculated from these data agree closely with those represented by term formulas herein proposed. Vibrational constants for the ground electronic states of the two isotopic species, consistent with the theory of the isotope effect and with existing experimental data are, in ${\mathrm{cm}}^{-1\mathrm{}}$,