Gas-phase ion–molecule reactions in dilute mixtures of dimethyl ether in krypton. Bimolecular and clustering reactions

✍ Scribed by Andreas J. Illies

• Publisher: John Wiley and Sons
• Year: 1990
• Tongue: English
• Weight: 332 KB
• Volume: 25
• Category: Article
• ISSN: 1076-5174
• DOI: 10.1002/oms.1210250115

✦ Synopsis

Abstract

The results of high‐pressure variable‐temperature and variable ionizing electron energy studies of gas‐phase ion‐molecule reactions of dimethyl ether in krypton are presented. Near the ionization threshold a series of peaks corresponding to (CH~3~OCH~3~)~n~H^+^ (n = 1‐4) clusters are observed. At higher ionizing electron energies, two new series of peaks appear, corresponding to [CH~3~OCH~2~]^+^(CH~3~OCH~3~)~n~ and [(CH~3~)~3~O]^+^ (CH~3~OCH~3~)~n~ clusters. The onium ion, [(CH~3~)~3~O]^+^, has been previously reported at elevated temperatures under methane chemical ionization conditions. It was suggested that the onium ion is formed by reaction of (CH~3~)~2~OH^+^ with CH~3~OCH~3~ with subsequent elimination of methanel, i.e. by fragmentation of an adduct ion. The present results strongly suggest that, under our conditions, [CH~3~OCH~2~]^+^ rather than thermal (CH~3~)~3~OH^+^, is the precursor to [(CH~3~)~3~O]^+^.