Fragmentation of imine-type meta-bridged bis(benzo crown ethers) under electron impact

✍ Scribed by K. B. Reiche; I. Starke; E. Kleinpeter; H.-J. Holdt; K. Pihlaja; P. Oksman; V. Ovcharenko

• Publisher: John Wiley and Sons
• Year: 1999
• Tongue: English
• Weight: 81 KB
• Volume: 13
• Category: Article
• ISSN: 0951-4198
• DOI: 10.1002/(sici)1097-0231(19990315)13:5<449::aid-rcm507>3.0.co;2-o

✦ Synopsis

Electron impact (EI) spectra of polymethylene-bridged carbonylhydrazones of 4'-formylbis(benzo-15crown-5 ether)s, their 18-crown-6 analogs, and their complexes with alkali cations (Na , K , and Cs ) were studied. Evidently, there are three main routes of fragmentation, including two types of McLafferty rearrangements and the formation of an azine species. The products of the McLafferty rearrangements fragment further to two ions both with the mass number (m/z 105) but different elemental compositions (C 6 H 5 N 2 and C 6 H 3 NO). No loss of ammonia was detected, in contrast to earlier observations. The ring size of the crown moieties had no influence on their decomposition behavior, but the length of the methylene bridges affected the fragmentation patterns of these compounds mainly due to increasing flexibility. The EI technique could not be used to estimate complexation tendencies or to obtain information on the stoichiometry of the bis(benzo crown ether) complexes.