The CBS-QB3 model chemistry predicts that the title ion-molecule reaction, of potential interest in astrochemistry, yields a stable head-to-tail dimer, [HC{double bond, long}N-CH2C(H)C{triple bond, long}N]{radical dot}+(D1). Cyclization of D1 into ionized pyrimidine seems possible, but the initiating 1,2-H shift is close in energy to back-dissociation into CH2{double bond, long}C(H)CN{radical dot}+(AN) + HCN. Less energy demanding is formation of the H-bridged isomers [CH2{double bond, long}C(CN)H--N{triple bond, long}CH]{radical dot}+and [HC{triple bond, long}N--HC(H){double bond, long}C(H)CN]{radical dot}+, whose HCN component may catalyze isomerization of AN into CH2{double bond, long}C{double bond, long}C{double bond, long}NH{radical dot}+(AN1) and CH{double bond, long}C(H)C{double bond, long}NH{radical dot}+(AN2) respectively. Tandem mass spectrometry based experiments using15N/13C labelling show that cyclization of D1 does not occur and that AN1 is the predominant reaction product instead.

dx.doi.org/10.1016/j.cplett.2009.10.017, hdl.handle.net/1765/24310
Chemical Physics Letters
Erasmus MC: University Medical Center Rotterdam

Ervasti, H.K, Jobst, K.J, Gerbaux, P, Burgers, P.C, Ruttink, P.J.A, & Terlouw, J.K. (2009). The reaction of the acrylonitrile ion CH2{double bond, long}CH-C{triple bond, long}N{radical dot}+ with HCN: Proton-transport catalysis vs formation of ionized pyrimidine. Chemical Physics Letters, 482(4-6), 211–216. doi:10.1016/j.cplett.2009.10.017