Transalkylierung und protonenkatalysierte C-C-Spaltung bei n-Butyl- und irc-Pentylbenzol in der Gasphase

C . C . V a n d e S a n d e u n d F . V a n G a e v e r L a b o r a t o r y for Organic Mass Spec t rometry , State Univers i ty o f Gent , B e l g i u m Z . Natur forsch . 3 4 b , 495-501 (1979) ; e ingegangen a m 8. D e z e m b e r 1978 Chemical Ionizat ion, Carbocations, H y d r o c a r b o n s T h e invest igation o f several 1 3 carbon and deuter ium labelled n b u t y l a n d n -penty l benzenes demonstrate that chemical ionizat ion (reagent g a s : methane ) induces specific c a r b o n c a r b o n b o n d cleavages o f the a lkyl group . T h e ex tent o f c o m p e t i n g react ion channels as f or instance direct alkene e l imination versus dea lky lat ion / reprotonat ion is analyzed . Partial hydrogen exchange processes b e t w e e n reagent ions and substrate molecules are restricted to the phenyl ring. Intramolecu lar e x c h a n g e react ions be tween the side chain and the aromatic ring which are typ i ca l f o r the o p e n shell molecu lar ions o f a lkyl benzenes are not observed for analogous c losed shell cat ions.