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RESEARCH PRODUCT

Conformational equilibrium and intramolecular hydrogen bond of 4′X and 4X substituted 2′(OH)chalcones

C.a. PonceA.c. DeviaFrancisco TomásF.h. Ferretti

subject

CrystallographyHydrogen bondComputational chemistryChemistryIntramolecular forceChemical stabilityPhysical and Theoretical ChemistryCondensed Matter PhysicsBiochemistryConformational isomerismCis–trans isomerism

description

Abstract By using the AM1 method on 4X and 4′X substituted 2′(OH)chalcones (X=H, OH, F, Cl, CH 3 , CH 3 O, N(CH 3 ) 2 , and NO 2 ), certain currently unclear structural characteristics, conformational equilibria, intramolecular hydrogen bonds and UV spectroscopic properties had been clarified. The compounds studied have non-planar structures. The 2′(OH),4′Xchalcones only present the trans - s - cis conformation. trans - s - cis and trans - s - trans conformers of 2′(OH),4X-chalcones have a comparable thermodynamic stability. For these chalcones, a conformational equilibrium at 298 K exists, with 91% of the trans - s - cis form. The proposal of analyzing the intramolecular hydrogen bond of 2′(OH),4X-chalcones as an intramolecular proton-transfer reaction, is acceptable because the results and theoretical prediction of this study agree well with available UV spectroscopic experimental data.

yearjournalcountryeditionlanguage
1999-12-01Journal of Molecular Structure: THEOCHEM
https://doi.org/10.1016/s0166-1280(99)00239-0