Abstract A novel pyridazin-3(2H)-one derivative, (E)-6-(4-methylstyryl)-4,5-dihydropyridazin-3(2H)-one (3) has been synthesized and characterized by FT-IR, UV–vis, 1H- and 13C NMR, TGA/DTA thermal analysis and single-crystal X-ray diffraction. Furthermore, the molecular geometry, vibrational frequencies, electronic absorption spectra, chemical shift values, HOMO-LUMO analysis, frontier molecular orbital (FMO) and molecular electrostatic potential (MEP) surface map of the title compound were calculated using DFT/B3LYP method with 6–31+G (d,p) basis set. A comparison among the experimental and calculated results indicates that the vibrational frequencies, maximum electronic absorption wavelengths and chemical shift values are in a good agreement with each other. The intermolecular interactions in the crystal structure were investigated using Hirshfeld surface analysis. TGA/DTA thermal analysis revealed that the title compound is thermostable to its melting point.

中文翻译：

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(E)-6-(4-methylstyryl)-4,5-dihydropyridazin-3(2H)-one 的合成、X 射线晶体学、振动光谱、热和 DFT 研究

摘要 合成了一种新型哒嗪-3(2H)-one 衍生物(E)-6-(4-甲基苯乙烯基)-4,5-二氢哒嗪-3(2H)-one (3)，并通过红外光谱表征， UV-vis、1H-和 13C NMR、TGA/DTA 热分析和单晶 X 射线衍射。此外，标题化合物的分子几何、振动频率、电子吸收光谱、化学位移值、HOMO-LUMO 分析、前沿分子轨道 (FMO) 和分子静电势 (MEP) 表面图使用 DFT/B3LYP 方法计算，6 –31+G (d,p) 基组。实验和计算结果的比较表明，振动频率、最大电子吸收波长和化学位移值相互吻合。使用 Hirshfeld 表面分析研究了晶体结构中的分子间相互作用。TGA/DTA 热分析表明标题化合物对其熔点是热稳定的。