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

• Published in: Journal of molecular structure 2018-11, Vol.1171, p.564-577
• Main Authors: Chethan Prathap, K.N., Lokanath, N.K.
• Format: Article
• Language: English
• Subjects: Coumarin; Density functional theory; Natural bond orbitals; Single crystal X-ray diffraction; UV–Vis
• ISSN: 0022-2860; 1872-8014
• DOI: 10.1016/j.molstruc.2018.06.022

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 °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⋯H and O⋯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. [Display omitted] •Three novel coumarin benzenesulfonylhydrazide hybrids were synthesized and characterized.•The structures were confirmed by single crystal X-ray diffraction method.•Structural optimization and quantum chemical calculations were carried out using DFT.•Electron delocalization and hyperconjugation interactions were studied.•One of the compounds might be a promising NLO material.