MICROWAVE SPECTRUM AND STRUCTURE OF VINYL FLUORIDE OZONIDE

Abstract

The microwave spectra of six isotopic species of vinyl fluoride ozonide (3-fluoro-1, 2, 4-trioxolane, $HFCOOCH_{2}O$ have been assigned to date; the normal species, $\alpha-D_{1}$, and $cis-D_{1}, D_{3}, ^{18}O$ (either), and $^{18}O_{3}$. These data are consistent with an $O_{p} – O_{p}$ twisted half chair conformation with the fluorine occupying an axial position. The data have been analyzed using a combination of Typke’s multiple substitution $r_{s}$ method and direct least squares ($r_{o}$) fitting. A complete structural determination is not possible without assuming three structural parameters. The most plausible structures obtained suggest the influence of an anomeric effect, i.e., a long C-F bond and shortening of both C-O bonds adjacent to the fluorine moiety.