Subtle solvation behaviour of a biofuel additive: the methanol complex with 2,5-dimethylfuran
| Autor: | Martin A. Suhm, Anja Poblotzki, Jonas Altnöder |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2016 |
| Předmět: |
010304 chemical physics
Hydrogen Stereochemistry Hydrogen bond 2 5-Dimethylfuran Intermolecular force Solvation biofuel additive methanol complex 2 5-dimethylfuran General Physics and Astronomy chemistry.chemical_element 010402 general chemistry 01 natural sciences 0104 chemical sciences chemistry.chemical_compound chemistry Chemical physics Furan 0103 physical sciences Methanol Physical and Theoretical Chemistry Methyl group |
| Popis: | Methanol is shown to engage two nearly equivalent solvation sites in 2,5-dimethylfuran, the electronrich p cloud and the electron-deficient oxygen site. The latter only wins by a slight margin, thanks to the methyl group undergoing secondary interactions with the ring. These secondary attractions reduce the hydrogen bond-induced OH frequency shift of the OH–O contact, whereas the p cloud allows for a combined action of both binding mechanisms in the OH–p arrangement. In total, the hydrophobic character of 2,5-dimethylfuran is well reflected in the weak pair interactions, as judged by the small solvation shifts. Methanol solvation of 2,3-benzofuran is revisited and shown to be more ambiguous than previously thought, involving competition between five- and six-ring p clouds and the oxygen site for the OH group. The six-ring p cloud is slightly preferred. FTIR spectroscopy in supersonic jets is in systematic agreement with dispersion-corrected harmonic B3LYP and also B2PLYP predictions for these competing furan docking sites. Deuteration of the OH group helps to identify the docking sites because of its attenuated zero-point energy weakening effect on localized hydrogen bonds. Extension to less methylated furans is proposed in the context of a future forecasting competition for the performance of quantum chemical methods for intermolecular interactions. peerReviewed |
| Databáze: | OpenAIRE |
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