Open AccessThis article is
- freely available
Deuterium Isotope Effects on 13C-NMR Chemical Shifts of 10-Hydroxybenzo[h]quinolines
Department of Science, Systems and Models, Roskilde University, P.O. Box 260, DK-4000 Roskilde, Denmark
Institute of Organic Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, 01-224 Warsaw, Poland
* Author to whom correspondence should be addressed.
Received: 1 March 2013; in revised form: 9 April 2013 / Accepted: 15 April 2013 / Published: 17 April 2013
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
Citations to this Article
Cite This Article
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.
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.
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.