Theoretical study on gas-phase proton transfer reactions between π-proton-donor and π-acceptor systems

Abstract

Three proton transfer (PT) reactions ( a) HC(H)CH ++C 2H 2→C 2H 2+HC(H)CH +, ( b) HC(H)CH ++C 2H 4→C 2H 2+H 2C(H)CH 2 +, and ( c) H 2C(H)CH 2 ++C 2H 4→C 2H 4+H 2C(H)CH 2 + are theoretically studied. High-level calculations show that the electron correlation plays a crucial role in such processes. The direct π-attack PT mechanism in the cross arrangement is revealed, and symmetrical and asymmetrical PT pathways are suggested between the proton-bound C 2H 2 and C 2H 2 (or C 2H 4 ) moieties and between two proton-bound C 2H 4 moieties, respectively. This study may provide the first theoretical results on the π-proton-donor to π-acceptor PT systems.