Three novel coumarin-benzenesulfonylhydrazide hybrids: Synthesis, characterization, crystal structure, Hirshfeld surface, DFT and NBO studies

Cytotoxic and many more interesting biological properties of coumarin derivatives make them an important class of heterocyclic compounds of pharmaceutical interest. They have also been studied extensively for their opto-electronic applications. Three novel coumarin-benzenesulfonylhydrazide hybrids were synthesized by condensation reaction, spectrochemically characterized and structures were confirmed by X-ray diffraction (XRD) method. In addition, their thermal and optical properties were investigated using thermogravimetric analysis and UV visible spectroscopy which revealed that all the three compounds are thermally stable up to a temperature of 190 degrees C and exhibit high absorbance in the near UV region. The diverse intermolecular interactions exhibited by three novel coumarin derivatives were studied by crystal packing and Hirshfeld surface analysis and observed that H center dot center dot center dot H and O center dot center dot center dot H interactions contribute to about 80% of the total intermolecular interactions. Further the coordinates were optimized by DFT calculations with B3LYP hybrid functionals at 6311 + G(d,p) level of theory. The optimized structural parameters showed very good correlation with those determined by XRD method. Frontier molecular orbitals (HOMO-LUMO), their energy gap and associated parameters were determined. Natural bond orbital analysis was carried out to explore inter/intra molecular interactions; electron delocalization and conjugative interactions. One of the coumarin derivatives shows very high hyperpolarizability value, which could be a potential NLO material. (C) 2018 Elsevier B.V. All rights reserved.