SPECTROSCOPY OF (BENZENE)(ACETIC ACID)_n CLUSTERS, EVEN/ODD ALTERNATION AND UNUSUAL ABUNDANCE OF THE (BENZENE)_2~+·(ACETIC ACID)_8 CLUSTER

摘要

Resonant two-photon ionization (R2PI) spectra of benzene-acetic acid binary clusters BA_n, with n = 1-6 have been measured. The results indicate that cluster formation from acetic acid vapor proceeds mainly via the association of pre-formed hydrogen-bonded dimers. The structures of the clusters and the dynamics of solvent evaporation reflect the special stability of the hydrogen bonded cyclic acetic acid clusters. A remarkable periodicity in the ion intensity of the binary clusters is observed with clusters containing an even number of acetic acid molecules being more abundant. This effect is attributed to the formation of multiple cyclic dimers as a result of clustering from a dimer-rich vapor phase. Evidence is presented for the special stability of the B_2A_8 ion, which is proposed to consist of a benzene dimer cation entrapped between two acetic acid tetramers.