Intramolecular H···H Interactions for the Crystal Structures of [4-((<i>E</i>)-But-1-enyl)-2,6-dimethoxyphenyl]pyridine-3-carboxylate and [4-((<i>E</i>)-Pent-1-enyl)-2,6-dimethoxyphenyl]pyridine-3-carboxylate; DFT Calculations on Modeled Styrene Derivatives

The crystal and molecular structures of [4-((E)-but-1-enyl)-2,6-dimethoxyphenyl]pyridine-3-carboxylate (BDMP) and [4-((E)-pent-1-enyl)-2,6-dimethoxyphenyl]pyridine-3-carboxylate (PDMP) are investigated by low-temperature X-ray diffraction measurements. The geometries of these molecules indicate that intramolecular dihydrogen bonds may exist for these structures. The use of the Bader theory supports this statement. To analyze the nature of such interactions, model calculations on styrene and its derivatives have been performed at B3LYP/6-311++G** level of theory.