Article ID Journal Published Year Pages File Type
1404920 Journal of Molecular Structure 2015 9 Pages PDF
Abstract

•E-3-(x-pyridyl)propenoic acids (x = 2, 3 or 4) were synthesized.•The structure forming abilities were investigated.•Energies and bond lengths of CH⋯N H-bonds were determined.•Conformational behaviour of the acids and the zwitterionic forms were studied.

The conformational as well as the structure-forming properties of E-3-(x-pyridyl)propenoic acids (x = 2, 3 or 4) have been studied with a combination of computational and spectroscopic methods. IR spectroscopy revealed that in the solid state the zwitterionic species predominate, while NMR measurements showed that dimers, kept together by strong CO⋯HO hydrogen bonds, were formed in a dipolar aprotic solvent (DMSO). In concentrated solution, extended aggregation occurred through the cooperative effect of (aromatic) CH⋯N weak hydrogen bonds. Conformational search was performed at the HF/6-31G(d,p) level of theory. Comparison with experimental values as well as benchmarking calculations at several different levels of theory to probe the performance of the methods, B3LYP/6-31G++(d,p) method was found to be able to provide reasonable geometries as well as quantitative formation energies for the dimers and the tetramers, too.

Related Topics
Physical Sciences and Engineering Chemistry Organic Chemistry
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