Sulphonamide chalcones: conformationally diverse yet optically similar

Abstract

In this paper, we present the synthesis of three chalcone analogues and their spectroscopic, structural and optical characterization. The influence of the different substituents on the crystalline structure and on their optical properties was evaluated. The effects of derivatization on the chalcones, both at the molecular and supramolecular levels, were evaluated. Also, the molar absorptivity, the first hyperpolarizability b and the two-photon absorption cross-section s2PA were obtained. The extended structures in each compound are stabilized by hydrogen-bonded dimers and by a pseudo-ring formed from an intramolecular H-bond. It was observed that more voluminous substituents, such as chlorine, contribute to the deviation from planarity. Although many effects were observed in molecular structures of these analogues when in solid form, experimental results of linear and nonlinear optical (NLO) properties showed that the optical properties were not as much influenced in solution. In addition, and to support some experimental results, the theoretical first hyperpolarizability was calculated and showed good agreement with experimental results, which are approximately 10 x 10-30 cm5/esu.