A comparison of hydrogen-bonded and van der Waals isomers of phenol⋅⋅nitrogen and phenol⋅⋅carbon monoxide: An ab initio study

Abstract

The hydrogen-bonded and van der Waals isomers of phenol⋅⋅nitrogen and phenol⋅⋅carbon monoxide in their neutral electronic (S0) and cation ground state (D0) were studied using ab initio HF/6-31G*, MP2/6-31G*, and B3LYP/6-31G* methods. The hydrogen-bonded isomers have the ligand bound via the hydroxyl group of the phenol ring, while the van der Waals isomers studied have the ligand located above the aromatic ring. For both complexes, the hydrogen-bonded isomer was found to be the most stable form for both the S0 and the D0 states. For phenol⋅⋅carbon monoxide, twice as many isomers as compared to phenol⋅⋅nitrogen were found. The hydrogen-bonded isomer with the carbon end bonded to the hydroxyl group was the most stable structure for both the S0 and the D0 states.

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.…”