Molecules 2013, 18(4), 4544-4560; doi:10.3390/molecules18044544
Article

Deuterium Isotope Effects on 13C-NMR Chemical Shifts of 10-Hydroxybenzo[h]quinolines

Received: 1 March 2013; in revised form: 9 April 2013 / Accepted: 15 April 2013 / Published: 17 April 2013
(This article belongs to the Special Issue Isotope Effects)
This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Abstract: Deuterium isotope effects on 13C-NMR chemical shifts are investigated in a series of 10-hydroxybenzo[h]quinolines (HBQ’s) The OH proton is deuteriated. The isotope effects on 13C chemical shifts in these hydrogen bonded systems are rather unusual. The formal four-bond effects are found to be negative, indicating transmission via the hydrogen bond. In addition unusual long-range effects are seen. Structures, NMR chemical shifts and changes in nuclear shieldings upon deuteriation are calculated using DFT methods. Two-bond deuterium isotope effects on 13C chemical shifts are correlated with calculated OH stretching frequencies. Isotope effects on chemical shifts are calculated for systems with OH exchanged by OD. Hydrogen bond potentials are discussed. New and more soluble nitro derivatives are synthesized.
Keywords: 10-hydroxybenzo[h]quinolones; deuterium isotope effects on 13C chemical shifts; intramolecular hydrogen bonds; hydrogen bond potentials; DFT calculations
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MDPI and ACS Style

Hansen, P.E.; Kamounah, F.S.; Gryko, D.T. Deuterium Isotope Effects on 13C-NMR Chemical Shifts of 10-Hydroxybenzo[h]quinolines. Molecules 2013, 18, 4544-4560.

AMA Style

Hansen PE, Kamounah FS, Gryko DT. Deuterium Isotope Effects on 13C-NMR Chemical Shifts of 10-Hydroxybenzo[h]quinolines. Molecules. 2013; 18(4):4544-4560.

Chicago/Turabian Style

Hansen, Poul E.; Kamounah, Fadhil S.; Gryko, Daniel T. 2013. "Deuterium Isotope Effects on 13C-NMR Chemical Shifts of 10-Hydroxybenzo[h]quinolines." Molecules 18, no. 4: 4544-4560.

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