ION-MOLECULE REACTIONS OF OXYGENATED SPECIES . PROTON-TRANSFER REACTIONS INVOLVING CHO+

The ionic reactions of the major ions in the mass spectra of formaldehyde, acetaldehyde, ethylene oxide, dimethyl ether, vinyl formate, and formaldehyde-DaO mixtures have been studied and rate constants determined for ions of 2.4-eV exit energy. The major reaction involves formation of the protonated molecule. The rate constants for transfer of a proton from CHO + to a neutral molecule M vary from 1.28×10-4 cm3 molecule-1-sec-1 (M = D2O) to 2.7×10-9 cm3 molecule-1-sec-1 (M=vinyl formate). The rate constants are shown to be in reasonable agreement with theoretical predictions.