Structure of Ozone from the Microwave Spectrum between 9000 and 45 000 Mc

Abstract

Although there have been numerous investigations of the structure of ozone during the last thirty years, no studies yielded universally accepted structures until the recent infrared and microwave work. The microwave spectrum gives structural information which can be interpreted unambiguously and which is more accurate than that obtained by other methods. In this study the rotational spectra have been obtained for six isotopic ozone molecules between 9000 and 45 000 Mc. The spectra of four of them have been identified to the extent necessary to determine the spectral constants, from which moments of inertia have been calculated. By taking the moments of inertia for a molecule two at a time, structural parameters of the molecules have been calculated. Because of the inertia defect, the three different sets of parameters for each molecule have small discrepancies. There is remarkable consistency between the parameters for the different molecules. Although the resultant bond length of 1.278±0.002 A is consistent with the electron diffraction value of 1.26±0.02 A, the apex angle value of 116° 45′±30′ is inconsistent with the diffraction value of 127°±3°. The dipole moment of ozone has been determined to be 0.58±0.05 Debye unit from the Stark effects of two low J‐transitions.