Evidence for a strong intermolecular bond in the phenolṡN2 cation

S. R. Haines*, W. D. Geppert, D. M. Chapman, Mark J. Watkins, C. E.H. Dessent, M. C.R. Cockett, K. Müller-Dethlefs

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review


The phenolṡN2 complex cation has been studied with a combination of two-color resonant zero kinetic energy (ZEKE) and mass analyzed threshold ionization (MATI) spectroscopies to probe the interaction of a polar cation with a quadrupolar solvent molecule. Extended vibrational progressions are observed in three modes which are assigned as the in-plane bend (35 cm-1), the stretch (117 cm-1), and in-plane wag (130 cm-1) intermolecular vibrations, and are consistent with a structure where the N2 forms a directional bond to the phenol OH group in the plane of the aromatic ring. Ab initio calculations at the UMP2/6-31G*, UHF/cc-pVDZ, and UMP2/cc-pVDZ levels of theory support this assignment. The spectra also provide a value for the adiabatic ionization energy (67423cm-1±4.5cm-1) and an estimate of the dissociation energy of the cluster (1650±20cm-1) which illustrate that the quadrupolar nitrogen molecule binds considerably more strongly to the phenol cation than a rare gas atom. These results constitute the first report of an aromaticṡN2 complex where the interaction can be described in terms of weak hydrogen bonding, rather than in terms of a van der Waals bond to the π-system of the benzene ring.

Original languageEnglish
Pages (from-to)9244-9251
Number of pages8
JournalJournal of Chemical Physics
Issue number21
Publication statusPublished - 1 Dec 1998

Cite this