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dispersion, molecular complexes, non-covalent interactions, rotational spectroscopy, vibrational spectroscopy
Abstract:
Dispersion interactions can play an important role in understanding unusual binding behaviors. This is illustrated by a systematic study of the structural preferences of diphenyl ether (DPE)–alcohol aggregates, for which OH⋅⋅⋅O‐bound or OH⋅⋅⋅π‐bound isomers can be formed. The investigation was performed through a multi‐spectroscopic approach including IR/UV and microwave methods, combined with a detailed theoretical analysis. The resulting solvent‐size‐dependent trend for the structural preference turns out to be counter‐intuitive: the hydrogen‐bonded OH⋅⋅⋅O structures become more stable for larger alcohols, which are expected to be stronger dispersion energy donors and thus should prefer an OH⋅⋅⋅π arrangement. Dispersion interactions in combination with the twisting of the ether upon solvent aggregation are key for understanding this preference.