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–D2O 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 × 10−9 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.