Synthesis, crystal structure, exploration of the supramolecular assembly through Hirshfeld surface analysis of new 2,4-dihydro-1H-1,2,4-triazole-3-selones and 3,3'-di(4H-1,2,4-triazolyl)diselenides

The reaction of aromatic ring-substituted isoselenocyanates with 2-thiopheacetic and 4-pyridinecarboxylic acid hydrazides yielded selenosemicarbazides, which were further converted into previously unknown 1,2,4-triazole-3-selones and 3,3'-di(4H-1, 2,4-triazolyl)diselenides. The structure of the obtained compounds was studied by X-ray diffraction analysis and NMR spectroscopy. Theoretically, the reactivity and nonlinear optical (NLO) properties were predicted by using the DFT-BELYP functional. Charge separation and orbital analysis were performed by using the frontier molecular orbital (FMO) and natural population analysis (NPA). 5aa, 5ca, and 5ab show significantly reduced HOMO-LUMO gaps and ionization potential (IP) among the other compounds. The density of states (DOS) spectra was plotted to get a pictorial representation of orbital and their energies. The highest β o value of 1754.31 au is obtained for 7fb which is indicating its excellent NLO properties. Nature and strength of Intermolecular interactions in crystal packing is considered through Hirshfeld surface (HS) analysis using the CrystalExplorer. Hence, the studied compounds have significant reactivity and optical and NLO properties and may open a new door in searching for new NLO materials.