Influence of solvents on intramolecular hydrogen bonds with large proton polarizability

doi:10.1016/0022-2364(82)90070-1

Journal of Magnetic Resonance (1969)

Volume 48, Issue 3, July 1982, Pages 361-366

Journal of Magnetic ...

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Abstract

A large number of compounds with intramolecular hydrogen bonds with great proton polarizability were studied by ¹H NMR in solvents of various polarities. With the homoconjugated hydrogen bonds, small changes of the chemical shift of the hydrogen-bonded proton are observed with increasing polarity of the solvent, whereby the signal shifts toward lower field. This effect is explained by increasing removal of the counterions from the homoconjugated hydrogen bonds and thus, by decreasing induced dipole interaction of the counterions and the hydrogen bonds with great proton polarizability. In the case of heteroconjugated hydrogen bonds analogous but much greater shifts are observed. They are explained by a shift of the OH…N ⇌ O⁻…H⁺N equilibria to the right-hand side with increasing polarity of the solvent. With hydrogen bonds showing no great proton polarizability these effects do not occur.

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Influence of solvents on intramolecular hydrogen bonds with large proton polarizability

Abstract

Chem. Phys. Lett.

Chem. Phys. Lett.

J. Chem. Soc. Faraday Trans. 2

J. Mol. Struct.

J. Chem. Soc. Faraday Trans. 2

Can. J. Chem.

Z. Phys. Chem. Frankfurt

Z. Phys. Chem. Frankfurt

Org. Mag. Chem.

Org. Mag. Chem.

Chem. Phys. Lett.

J. Phys. Chem.

Chem. Phys. Lett.

J. Chem. Soc. Faraday Trans. 2

Chem. Phys. Lett.

J. Mol. Struct.

Org. Magn. Reson.

J. Phys. Chem.