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RESEARCH PRODUCT
Structure and vibrational features of the protic ionic liquid 1,8-diazabicyclo[5.4.0]-undec-7-ene-8-ium bis(trifluoromethanesulfonyl)amide, [DBUH][TFSI]
Angelo SarraPhilip ChaterFrancesco TrequattriniOriele PalumboAlessandro TrioloAnnalisa PaoloneGiovanni BattistaappetecchiFabrizio Lo CelsoOlga Russinasubject
Hydrogen bondingMaterials scienceProtic Ionic LiquidBase (chemistry)DFT calculationMolecular Dynamics010402 general chemistry01 natural scienceschemistry.chemical_compoundDFT calculation; Far-ir spectroscopy; Hydrogen bonding; Molecular Dynamics; Protic Ionic Liquid; X-ray scatteringPhase (matter)Materials ChemistryFar-ir spectroscopyPhysical and Theoretical ChemistryConformational isomerismSpectroscopychemistry.chemical_classification010405 organic chemistryHydrogen bondX-ray scatteringCondensed Matter PhysicsAtomic and Molecular Physics and Optics0104 chemical sciencesElectronic Optical and Magnetic MaterialsCrystallography18-Diazabicyclo[5.4.0]undec-7-enechemistryAbsorption bandIonic liquidDispersion (chemistry)description
Abstract The Protic Ionic Liquid (PIL) formed by neutralization of the super-strong base 1,7-diazabicyclo[5.4.0]undec-7-ene (DBU) with the super-strong acid bis(trifluoromethanesulfonyl)-imide (TFSI), indicated as [DBUH][TFSI], has been investigated. Its chemical physical properties and structural features have been explored using a synergy of experimental and computational tools. Molecular Dynamics-rationalised X-ray diffraction patterns highlight the major role played by hydrogen bonding (HB) in affecting morphology in this PIL. A comparison between HB features in this and in related PILs has been presented, on the base of far-IR experiments and DFT analysis. Indications of a weaker HB interaction in [DBUH][TFSI] in comparison with [DBUH][TfO], consistently with their ΔpKa difference, have been observed and rationalised in terms of geometrical properties of the main conformers contributing to the experimental spectra. In the liquid phase of [DBUH][TFSI] a particularly large conformational disorder is observed and the corresponding large dispersion of the frequencies of the HB stretching modes leads to a broad absorption band without a well defined peak. On the contrary, well detectable HB related absorptions are observable in the solid phase of [DBUH][TFSI] and at all temperatures in [DBU][TfO], where less configurational disorder occurs.
| year | journal | country | edition | language |
|---|---|---|---|---|
| 2022-02-01 | Journal of Molecular Liquids |