Abstract

GOMEZ-HURTADO, Mario A. et al. X-Ray diffraction and NMR studies of two chromenes from the reoots of Ageratina arsenei. Rev. latinoam. quím [online]. 2012, vol.40, n.3, pp.199-209. ISSN 0370-5943.

Eupatoriochromene (1) and ripariochromene B (2), isolated in good yields from the roots of Ageratina arsenei, were studied by X-ray diffraction analysis showing that, in the solid state, there is a distortion from planarity of the bicyclic system due to crystal packing besides several classical and non-classical hydrogen bond interactions. DFT B3LYP/DGDZVP calculations of eupatoriochromene (1) allowed comparison of the DFT bond distances with those obtained from the X-ray analysis, while GIAO calculations of the NMR shielding tensors were used to evaluate the chemical shift differences with respect to the experimental values measured in CDCl₃.

Keywords : Ageratina arsenei; eupatoriochromene; ripariochromene B; X-ray diffraction; non-classical hydrogen bond interactions; NMR; DFT calculations; GIAO method.

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