An infrared study of hydrogen bond stability in benzoic acid–trans-1,2-bis(4-pyridyl)ethylene complexes in the solid state and the implications for the design of supramolecular polymers

Abstract

Derivatives of benzoic acid were complexed with trans-1,2-bis(4-pyridyl)ethylene. Infrared spectroscopy was used to confirm complexation and a correlation was found between the value of ν-CO for the complex in the solid state and the pK_a of the benzoic acid derivative. The stabilities of the hydrogen bonds in the complexes were investigated by temperature dependent infrared spectroscopy. It was found that all of the complexes behaved in a similar way, the hydrogen bonds remained intact until the melting point of the complex was reached. The implications for the design of supramolecular polymers are discussed.