Theoretical and experimental study of aluminum ion–acetonitrile clusters

Abstract

The gas phase reactions between a singly charged aluminum ion and acetonitrile clusters are studied by a laser ablation-molecular beam method. Similar to metal ion–methanol clusters, two distinct intensity gaps of Al +(CHCN) n clusters are found. The first intensity gap occurs between n=4 and n=5, and the second is found between n=6 and n=7. Density functional calculations on the structures and energetic of the reactants and products are carried out at the B3LYP/6-31+G ∗ level in order to get a qualitative picture about the gross geometries and thermodynamic stability. For ionic clusters Al +(CHCN) n , there are two kinds of stable isomers. As the size of the cluster increases from two to four, the relative stability decreases gradually. According to the results of experiments, the signal intensity of clustered complex ions decreases with the size of the cluster increase from two to four. Good agreement between theory and experiment is found for ionic clusters Al +(CHCN) n .