Conformation of 2,2,2-Trifluoroethanol and the Solvation Structure of Its 2-Fluoropyridine Clusters

Abstract

The conformation of 2,2,2-trifluoroethanol (TFE) in the 2-fluoropyridine-(TFE) m -(H 2 O) n clusters in a supersonic jet has been investigated with fluorescence-detected infrared spectroscopy and quantum chemical calculations. It is common to the observed clusters that they form chain structures containing the weak interaction of the pyridyl CH with the fluorine or oxygen atom in the terminal TFE. The detectable conformation of TFE is gauche only even in the case of the existence of the strong base such as 2-fluoropyridine. This result is explained by the change in hyperconjugation among several dominant orbitals. The preference of the terminal TFE in the mixed clusters with TFE and water solvents is observed, which is ascribed to the stronger cooperative effect of TFE than water.

Ionic Fragmentation Mechanisms of 2,2,2‐Trifluoroethanol Following Excitation with Synchrotron Radiation

“…The m/z 31 signal remains the most intense one in all spectra measured in this energy region; this reveals that the rupture of the CÀC bond is the most important mechanism [Eq. (1)]. On the other hand, no evidence of the molecular ion is observed in the spectra, even at energies just above the first ionisation potential, which reveals the instability of M + C and its tendency towards fragmentation.…”

“…TFE is extensively used as a co-solvent because it promotes or stabilises the formation of the secondary structure of peptides and proteins; [1,2] this property has resulted in several studies on the structure and interactions present in the liquid phase. TFE is extensively used as a co-solvent because it promotes or stabilises the formation of the secondary structure of peptides and proteins; [1,2] this property has resulted in several studies on the structure and interactions present in the liquid phase.…”

“…2,2,2-Trifluoroethanol (TFE) is a colourless liquid with a wide variety of applications, ranging from chemical reagents and polar organic solvents to biochemical and industrial uses. TFE is extensively used as a co-solvent because it promotes or stabilises the formation of the secondary structure of peptides and proteins; [1,2] this property has resulted in several studies on the structure and interactions present in the liquid phase. [3] TFE presents several industrial applications, such as pharmaceutical uses as a starting material for some inhalation anaesthetics, [4] use in the preparation and treatment of nylon, [5] and as a working fluid for heat engines.…”

The Influence of the Position of the Double Bond and Ring Size on the Stability of Hydrogen Bonded Complexes

“…A particular case of atmospherically relevant alcohol in complex formation is the 2,2,2-trifluoroethanol (TFE), one of the widely used fluorinated alcohols that is available on a large commercial scale. It has been used in many reactions as solvent, cosolvent, catalyst, and it is also important for the preparation of many pharmaceuticals and other chemicals 9 – 12 . Increased production and use of TFE will lead to an increase of its emission into the atmosphere.…”

“…Hydrogen bonding interactions between TFE and various atmospheric components have been explored by many studies, both theoretically and experimentally. Hydrogen bonded complexes of TFE with ammonia, tetrahydrofuran or diethyl ether in the gas phase studied with Fourier transform infrared (FTIR) spectrometer have been reported, and the formation of these complexes were identified by observed red shifts of the OH-stretching fundamental transitions 9 , 15 . Using alcohols including TFE, ethanol (EtOH), and methanol (MeOH) as hydrogen bond donors, and dimethylamine (DMA) or trimethylamine (TMA) as acceptor, the strengths of the O−H···N hydrogen bond in the alcohol–amine complexes were examined using vapor phase FTIR spectroscopy and quantum chemical calculations.…”