Intracluster multiple trimeric cyclization of acrylonitrile clusters initiated by electron transfer from a potassium atom: Size-dependent pathways in metastable dissociation of K⁺(CH₂=CHCN)_n photoions

Intracluster bond-formation reactions, initiated by electron transfer, were investigated by photoionization mass spectrometry of clusters of a potassium atom and acrylonitrile. A frequency doubled output of a dye laser, pumped by a Nd:YAG laser, was used as a photoionization light source. In the photoionization mass spectrum of K(AN)_n, magic numbers were observed at n=3k (k=1-4). The coexistence of isomers, corresponding to the sequential cyclization reaction products, was shown from the observation of metastable dissociation and the calculation of decay rate constants by the Rice-Ramsperger-Kassel-Marcus theory.