Microwave Spectrum of Chlorine Dioxide. I. Rotational Assignment

The microwave spectrum of chlorine dioxide has been investigated and several rotational transitions assigned. The resulting rotational constants (in Mc) are: ${\mathrm{Cl}}^{35}$ ${\mathrm{O}}_2$: $A=52\mathrm{}072$, $B=9952\mathrm{}$, $C=8332\mathrm{}$; ${\mathrm{Cl}}^{37}$ ${\mathrm{O}}_2$: $A=50\mathrm{}725$, $B=9952\mathrm{}$, $C=8295\mathrm{}$. These constants are limited in precision by the presence of hyperfine structure which has been only approximately treated. The structural parameters of chlorine dioxide as obtained from the rotational constants are $r_{C\mathrm{l}-\mathrm{O}}=1.473\mathrm{}\pm 0.01$ A; Received 13 October 1960 DOI: https://doi.org/10.1103/PhysRev.121.1119 ©1961 American Physical Society