Synthesis, X-ray crystallography, vibrational spectroscopy, thermal and DFT studies of (E)-6-(4-methylstyryl)-4,5-dihydropyridazin-3(2H)-one

•Novel pyridazin-3(2H)-one derivative has been synthesized and characterized using FT-IR, UV–vis, 1H- and 13C NMR, and X-ray diffraction.•Quantum chemical calculations were carried out by DFT/B3LYP method.•The Hirshfeld and MEP surfaces analyses were investigated.•The thermal stability of the synthesized compound was also studied.