THE MICROWAVE SPECTRUM OF DIVINYLETHER

This work was supported by the National Science Foundation and the Petroleum Research Fund of the American Chemical Society. $^{1}$V. M. Rao and R. F. Curl, JR., J. Chem, Phys. 40, 3688 (1964).""Author Institution: Department of Chemistry, Rice UniversityThe microwave spectrum of divinylether ($CH_{2}CH)_{2}O$ has been studied and the assignments have been made for the ground state of one isomer. Rotational constants are A=15669.25, B=3221.11, and C=2790.19 MHz. Doublet splittings of about 53 MHz in the c-type Q-branch series ($J_{oJ}\rightarrow J_{I, J})$ were observed. The dipole moment was measured as, $\mu=0.782\pm 0.026, \mu_{a}=0.349\pm 0.012, \mu_{b}=0.662=0.009$, and $\mu_{c}=0.225\pm 0.035$ Debye. These results suggest that the conformer observed is fairly close in structure to the planar cistrans conformation. This structure is analogous to that found for vinyl $formate.^{1}$ However, the conformer observed for divinylether is definitely non-planar in contrast to that of vinyl formate. Presumably the hydrogen-hydrogen repulsion, indicated by the arrows is reduced by twisting out-of-plane. Doublet splittings in c-type lines are almost independent of J values suggesting inversion-type splittings of the energy levels