REACTION OF PROTONATED ACETALDEHYDE WITH METHANOL IN THE GAS-PHASE

The ion-molecule reactions between protonated acetaldehyde and methano l were explored on a quadrupole, quistor, quadrupole tandem mass spect rometer. In addition to proton transfer to methanol and subsequent met hanol ion-molecule chemistry, the protonated acetaldehyde-methanol add uct and methylated acetaldehyde could be detected. Experiments with la belled counterparts showed that the formation of methylated acetaldehy de corresponds to substitution of the oxygen-bound hydrogen of protona ted acetaldehyde by the methyl group of methanol. The reaction rates i nvolved and H-D exchange rates were determined.