Coumarin derivative, 7-hydroxy-3-(4-nitrophenyl)-coumarin (C15H9N1O5) was synthesized by knoevenagel condensation reaction by using 2,4-Dihydroxybenzladehyde and 4-nitrophenylacetonitrile. The title compound was characterized by FT-IR, NMR and LCMS spectral studies and finally, the structure was confirmed by X-ray diffraction studies. The crystal structure of the title compound displays a two-dimensional architecture. The compound exhibits both inter and intra-molecular hydrogen bonds of type O—H...O and C—H...O. In addition, DFT calculations and Hirshfeld surface analysis were carried to analyze nature of hydrogen bonding, inter-molecular interaction in crystal, and to examine the molecular shapes. The overlapping of atomic orbital along with their predicted energy is explained on the basis of HOMOLUMO energy gap calculations. Molecular electrostatic potential map was studied for predicting the reactive sites.

中文翻译：

---

7-羟基-3-(4-硝基苯基)香豆素的合成及单晶研究

香豆素衍生物7-羟基-3-(4-硝基苯基)-香豆素(C15H9N1O5)以2,4-二羟基苯甲醛和4-硝基苯乙腈为原料,通过knoevenagel缩合反应合成。通过 FT-IR、NMR 和 LCMS 光谱研究对标题化合物进行了表征，最后通过 X 射线衍射研究证实了其结构。标题化合物的晶体结构显示出二维结构。该化合物表现出分子间和分子内的OH-H...O和C-H...O型氢键。此外，还进行了DFT计算和Hirshfeld表面分析，分析了晶体中氢键的性质、分子间的相互作用，并检查了分子的形状。在 HOMOLUMO 能隙计算的基础上解释了原子轨道的重叠及其预测能量。