Muttiphoton Ionization of Benzene‐Ammonia Clusters: Intracluster Reaction and Cluster Ion Stability

摘要

AbstractNeutral benzene‐ammonia clusters, prepared in a supersonic expansion, were ionized using multiphoton ionization. The cluster ions were investigated with a time‐of‐flight mass spectrometer. The observed major cluster ions, under 355‐nm laser irradiation, resulting from prompt intracluster ion‐molecule reaction and fragmentation following ionization are (C6H6)m(NH3)nH+, m = 1–6, n = 1–4 and (C6H6)m+, m = 1–3. The results of isotopic labeling experiments clearly indicate that C6H6does not participate in intracluster ion‐molecule reactions to form (C6H6)m(NH3)nH+. A local maximum appears at n = 2 in the intensity distribution of (C6H6)m(NH3)nH+for each value of m under all experimental conditions. This finding indicates that (C6H6)m(NH3)2H+is more stable than any other (C6H5)m(NH3)mH+(n = 1