The Six Isomers of the Cyclohexanol Dimer: A Delicate Test for Dispersion Models |
| |
Authors: | Marcos Juanes,Imanol Usabiaga,Iker Le n,Luca Evangelisti,Jos A. Fern ndez,Alberto Lesarri |
| |
Affiliation: | Marcos Juanes,Imanol Usabiaga,Iker León,Luca Evangelisti,José A. Fernández,Alberto Lesarri |
| |
Abstract: | The cyclohexanol homodimer acts as a delicate test model of the role of dispersion forces in intermolecular association. Whereas phenol produces a single dimer, the suppression of π interactions and the larger conformational flexibility in cyclohexanol results in multiple isomerism, with six competing dimers of the free molecule being observed in a supersonic jet expansion. Rotational spectroscopy reveals accurate structural data, specifically the formation of homo‐ and heterochiral diastereoisomers and the presence of both equatorial and axial forms in the dimers. Four dispersion‐corrected density‐functional molecular orbital calculations were tested against the experiment, with B3LYP‐D3(BJ) offering good structural reproducibility with an Alrich's triple‐ζ basis set. However, the prediction of the dimer energetics is largely model‐dependent, thus offering a testbed for the validation of dispersion‐corrected computational models. |
| |
Keywords: | cyclohexanol hydrogen bonding jet spectroscopy molecular recognition rotational spectroscopy |
|
|