Fragmentation and rearrangement reactions in certain 1,2,3-triaryl-2-propen-1-ones following electron impact and chemical ionization
摘要:
AbstractThe electron impact (EI) and chemical ionization (CI) mass spectra of certain 1,2,3‐triaryl‐2‐propen‐1‐ones (TAPs) have been studied in detail with the help of exact mass measurements, deuterium labelling and metastable data. TheE‐ andZ‐isomeric pairs do not show any difference in their behaviour under EI or CH4CI conditions. EI‐induced rearangement reactions in the TAPs include aryl migration to carbonium ion centres. A study of the metastable transitions reveals aryl group interchange in the molecular ions prior to fragmentation. Under EI conditions loss of arene involves either C(2) or C(3) aryl groups while under CI conditions the C(1) aryl is lost as a neutral arene molecule. Mechanisms for the different fragmentation modes are given.