Hydrogen bonding. Part 1.—Equilibrium constants and enthalpies of complexation for monomeric carboxylic acids with N-methylpyrrolidinone in 1,1,1-trichloroethane

1986 ◽  
Vol 82 (11) ◽  
pp. 3501 ◽  
Author(s):  
Michael H. Abraham ◽  
Philip P. Duce ◽  
Ronald A. Schulz ◽  
Jeffrey J. Morris ◽  
Peter J. Taylor ◽  
...  
Keyword(s):  
Hydrogen Bonding ◽  
Carboxylic Acids ◽  
Equilibrium Constants

Hydrogen bonding in the gas phase: the thermodynamic properties of hydrogen fluoride-ether complexes and their far infrared spectra

1971 ◽  
Vol 322 (1548) ◽  
pp. 137-146 ◽  
Keyword(s):  
Hydrogen Bonding ◽  
Gas Phase ◽  
Infrared Spectra ◽  
Equilibrium Constants ◽  
Far Infrared ◽  
Methyl Ethyl ◽  
Rotational Contour ◽  
Stretching Vibration ◽  
Conformational Rearrangements ◽  
Far Infrared Spectra

The equilibrium constants of gas-phase complexes of HF with dimethyl, methyl ethyl and diethyl ether have been measured at several temperatures using the Benesi-Hildebrand approximation on the absorption band of the HF stretching vibration in the complex. From these, values of Δ H of — 43, — 38 and — 30 kJ mol -1 respectively, have been determined. They are interpreted in terms of conformational rearrangements of the ethers when they form hydrogen bonds. The far infrared spectra of the complexes with both HF and DF have also been recorded and in each case a band observed at around 180 cm -1 which is assigned to the intermolecular stretching mode of vibration. For the complex between HF and dimethyl ether a rotational contour has been observed at about 10 cm -1 .

Anion-molecule complexes in solution. II. The complexing of halide ions with acetylated β-D-glucopyranosyl derivatives

1968 ◽  
Vol 46 (20) ◽  
pp. 3263-3274 ◽  
Author(s):  
J. S. Martin ◽  
Jun-Ichi Hayami ◽  
R. U. Lemieux
Keyword(s):  
Hydrogen Bonding ◽  
Equilibrium Constants ◽  
Strong Dependence ◽  
Electrostatic Model ◽  
Halide Ions ◽  
Pyranose Ring

Tetra-O-acetyl-β-D-glucopyranosyl halides and phenoxides in solution in acetonitrile showed a specific deshielding of H-1, H-3, and H-5 on addition of tetraethylammonium halides. The shifts and equilibrium constants increased as the anion radius decreased. The ortho hydrogens of the phenoxide aglucons were also significantly deshielded. The strong dependence of the equilibrium constants of the phenoxide compounds on p-substituents indicated considerable involvement of the phenyl groups in a specific conformation. A simple electrostatic model was successful in correlating the energies and predicting the structures of the complexes. It was not necessary to postulate specific hydrogen bonding to account for association of the anion with an electrophilic region of the molecule. The calculations required specific orientations of acetoxy groups with respect to the pyranose ring which are consistent with those of related studies. In favorable circumstances, the method may be used as a probe for electrophilic regions in molecules.

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