Search

Besides well-known products of the gas-phase ozonolysis of ethylene, formic anhydride, glycolaldehyde, ethylene oxide, acetaldehyde and methanol have been detected by combined linear-reactor—infrared-matrix and microwave spectroscopy. Possible reaction mechanisms based on ab-initio and estimated thermochemical data are suggested taking into account the newly observed molecules.

The rotational spectrum of formic anhydride (C 2 H 2 O 3 ) has been studied and assigned in the frequency range from 8 to 40 GHz. The rotational constants, centrifugal distortion constants and the electric dipole moment have been determined for the ground vibrational state. The most stable conformation of the molecule has been determined.

The laser-induced excitation spectrum for the 0.0 band of the A 2 II → X 2 X + transition of CO + has been observed from an ion beam. Analysis of electron-bombardment excitation fluorescence in the same ion beam indicates radiative lifetime for the A 2 IIν′ = 0 state of CO + of 7.4 ± 1.0 μs.

The gas phase ozonolysis of vinylchloride has been investigated by linear reaction-infrared matrix and -microwave spectroscopy. The reaction is shown to produce formaldehyde and chloroethylene oxide, besides already known products. Implications for the reaction mechanism will be discussed.

In relation to several postulates of the ozonolysis mechanism, the stability and conformation of the hypothetical methylene peroxide molecule (CH 2 O 2 ) is investigated by an ab initio SCF MO calculation using a gaussian lobe function basis set of double zeta accuracy. The structure which has a three membered ring is found to be the most stable one amongst the conformations considered. The molecular electronic structure is discussed with the help of the electronic charge distribution in this species.