From hydrogen bond donor to acceptor: the effect of ethanol fluorination on the first solvating water molecule.

Supersonic jet FTIR spectra of the OH stretching vibrations in complexes of mono-, di- and trifluoroethanol with water are presented. In contrast to the non-fluorinated ethanol case, the fluorinated alcohols are all shown to act as O-H···O hydrogen bond donors towards water. This is found to be mostly a consequence of the intramolecular electron-withdrawing effect of the fluorine atoms and, with decreasing importance for increasing fluorination, due to the attractive intermolecular contact between one of the dangling water OH groups and the fluorine atoms.

A peptide co-solvent under scrutiny: self-aggregation of 2,2,2-trifluoroethanol.

Trifluoroethanol (TFE) and its aggregates are studied via supersonic jet FTIR and Raman spectroscopy as well as by quantum chemistry and simple force field approaches. A multi-slit nozzle is introduced to study collisionally excited clusters. Efforts are made to extract harmonic frequencies from experiment for better comparison to theory.

Quantitative chirality synchronization in trifluoroethanol dimers.

2,2,2-Trifluoroethanol molecules synchronize their transiently chiral gauche configurations upon dimerization in supersonic jet expansions, while they avoid an energetically competitive heteroconfigurational hydrogen bonded dimer topology predicted by extensive quantum chemical calculations.