Original scientific paper

Intrinsic Long Range Deuterium Isotope Effects on 13C NMR Chemical Shifts as a Conformational Probe of Benzene Derivatives

Dražen Vikić-Topić ; Ruđer Bošković Institute, Bijeni~ka 54, HR–10000 Zagreb, Croatia
Predrag Novak ; Ruđer Bošković Institute, Bijeni~ka 54, HR–10000 Zagreb, Croatia
Zlatko Meić ; Ruđer Bošković Institute, Bijeni~ka 54, HR–10000 Zagreb, Croatia
Janez Plavec ; National Institute of Chemistry, Hajdrihova 19, SI–1000 Ljubljana, Slovenia
Damir Kovaček ; Faculty of Food Technology and Biotechnology, Pierottijeva 6, HR–10000 Zagreb, Croatia

Abstract

13C NMR spectra of molecules containing one or two benzene rings linked with CH=CH₂, CH=CH (trans- or cis-), C≡C and CH=N groups revealed the existence of long range deuterium isotope effects on 13C chemical shifts. It was found that deuterium isotope effects over six bonds (6Δ) are related to the conformation of investigated molecules. Molecular torsional angles were calculated by ab initio HF/6–31G* and AM1 semi-empirical calculations. Very good linear correlations were established between experimentally observed 6Δ and theoretical torsional angles obtained from ab initio and semi-empirical calculations.

Keywords

¹³C NMR; long range deuterium isotope effects; conformational dependence

Hrčak ID:

132315

URI

https://hrcak.srce.hr/132315

Publication date:

1.12.1999.

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