Studies of hydrogen bonding in the vapor phase by measurement of thermal conductivity and molecular orbital calculations, 2,2,2-trifluoroethanol

Journal Article · Wed Jan 04 04:00:00 EST 1978 · J. Am. Chem. Soc.; (United States)

DOI:https://doi.org/10.1021/ja00469a013· OSTI ID:5308075

Curtiss, L A; Frurip, D J; Blander, M

The thermal conductivity of 2,2,2-trifluoroethanol vapor was measured in a modified thick hot-wire cell between 338 and 385 K at pressures ranging from approximately 100 to 1300 Torr (13.3 to 173 kPa). Analysis of the data indicates that molecular association to form a dimeric species is the main source of the enhancement of the thermal conductivity of the vapor. The enthalpy of association of the trifluoroethanol dimer is -4753 cal/mol and the entropy of association is -18.73 cal/mol K. Ab initio calculations were carried out on several rotational isomers of trifluoroethanol and on four possible dimer structures. The most stable dimer is a cyclic structure involving the gauche-staggered isomer of trifluoroethanol. An extra hydrogen bond due to the presence of the fluorines enhances the stability of the dimer compared to the methanol dimer.

• Research Organization: Argonne National Lab., IL
• OSTI ID: 5308075
• Journal Information: J. Am. Chem. Soc.; (United States), Journal Name: J. Am. Chem. Soc.; (United States) Vol. 100:1; ISSN JACSA
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400301* -- Organic Chemistry-- Chemical & Physicochemical Properties-- (-1987)
ALCOHOLS
CHEMICAL BONDS
DIMERS
HYDROXY COMPOUNDS
ISOMERS
MOLECULAR ORBITAL METHOD
MOLECULAR STRUCTURE
ORGANIC COMPOUNDS
ORGANIC FLUORINE COMPOUNDS
ORGANIC HALOGEN COMPOUNDS
PHYSICAL PROPERTIES
THERMAL CONDUCTIVITY
THERMODYNAMIC PROPERTIES