Evidence for a strong intermolecular bond in the phenol⋅N2 cation

Abstract

Competition between cation-π interactions and intermolecular hydrogen bonds inalkali metal ion-phenol clusters. II. Phenol trimer Structures and rearrangement reactions of 4 -aminophenol ( H 2 O ) 1 + and 3 -aminophenol ( H 2 O ) 1 + clusters J. Chem. Phys. 123, 074320 (2005); 10.1063/1.2008255 The energetics and structural properties of diazomethyl (HCNN) and cyanomidyl (HNCN) radicals and their related cations and anions from ab initio calculations J. Chem. Phys. 122, 064316 (2005); 10.1063/1.1844314 Intermolecular vibrations of the jet-cooled 2-pyridone2-hydroxypyridine mixed dimer, a model for tautomeric nucleic acid base pairsThe phenol•N 2 complex cation has been studied with a combination of two-color resonant zero kinetic energy ͑ZEKE͒ and mass analyzed threshold ionization ͑MATI͒ 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 Ϫ1 ͒, the stretch ͑117 cm Ϫ1 ͒, and in-plane wag ͑130 cm Ϫ1 ͒ intermolecular vibrations, and are consistent with a structure where the N 2 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 (67 423 cm Ϫ1 Ϯ4.5 cm Ϫ1 ) and an estimate of the dissociation energy of the cluster (1650 Ϯ20 cm Ϫ1 ) 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 aromatic•N 2 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 -system of the benzene ring.

ZEKE and Hole-Burning Spectroscopy of the Rotational Isomers of Resorcinol·CO

“…This procedure has been demonstrated to be reliable in a number of cases where additional experimental results have corroborated geometric structures obtained from this approach. A recent example is provided by the ZEKE spectrum of [phenol‚N 2 ] + , 14 where ab initio calculations pointed to a hydrogen-bonded in-plane structure, 15 which was subsequently supported by direct evidence from an infrared spectrum of the cation. 16 We have recently studied three rotational isomers of the resorcinol (1,3-dihydroxybenzene)‚H 2 O complex using resonance enhanced multiphoton ionization (REMPI) and ZEKE spectroscopies, along with ab initio calculations.…”

Determination of the Geometry Change of the Phenol Dimer upon Electronic Excitation

“…In the phenol dimer, dispersive interactions between the aromatic rings play an important structural role, while for most hydrogen-bonded phenol-X clusters (X = H 2 O, [6][7][8][9][10][11][12][13][14][15][16][17][18][19][20] CH 3 OH, [21][22][23] N 2 , [24][25][26][27][28][29] NH 3 , [30][31][32][33][34][35][36][37][38][39] CO [24,40] ) the hydrogen bond is by far the most important structure determining parameter.…”

Determining the Intermolecular Structure in the S0 and S1 States of the Phenol Dimer by Rotationally Resolved Electronic Spectroscopy

“…[1] The phenol dimer takes a special position, since one of the cluster constituents acts as proton donor and the other as proton acceptor. Dispersive interactions between the aromatic rings are most likely to play an important role in the structure, while for most of the other phenol-X clusters (X = H 2 O, [2][3][4][5][6][7][8][9][10][11][12][13][14][15] CH 3 OH, [16][17][18] N 2 , [19][20][21][22][23][24] NH 3 , [25][26][27][28][29][30][31][32][33][34] CO [19,35] ) the hydrogen bond is the main structure-determining parameter. Exceptions here are, of course, clusters of phenol with noble gases [36,37] or with CH 4 , [38] which are stabilized by pure van der Waals interactions.…”