Reactions of lead cluster ions with ethylene, propene, trans ‐butene, and cis ‐butene

Reactions of lead cluster cations and anions with ethylene, propene, and trans ‐and cis ‐butene have been studied using a home‐built reflectron time‐of‐flight mass spectrometer. Both the high‐ and low‐energy pathway reactions were observed in the lead cluster reactions. For ethylene, only association products [Pb k (C 2 H 4 ) n + ] were observed. For propene, both association products [Pb k (C 3 H 6 ) n + ], high‐energy pathway products [Pb k (CH 3 ) + ] and their further association products [Pb k (CH 3 ) m (C 3 H 6 ) n + ] were observed, while for butenes, besides the three kinds of products mentioned above, Pb k (C 4 H 8 ) n + ,Pb k CH 3 + and Pb k (CH 3 ) m (C 4 H 8 ) n + , low‐energy pathway products [Pb k C 4 H 6 + ,Pb k C 3 H 3(5) + , Pb k C 3 H 2(3) + (for cis‐butene only)] and their further association products [Pb k C 4 H 6 (C 4 H 8 ) n + , Pb k C 3 H 3(5) (C 4 H 8 ) n + ,Pb k C 3 H 2(3) (C 4 H 8 ) n + (for cis‐butene only)] were also observed. Bond selectivity and effects of steric hindrance were observed in the low‐energy pathway reactions of lead cluster cations with trans ‐ and cis ‐butene. The same anionic products, Pb k C m − , with nearly the same intensity distribution, were observed in the reactions of lead cluster anions with all four alkenes studied here. Some reaction mechanisms are proposed for these reactions.