Grafting 6-aminopenicillanic acid (6-APA) onto superparamagnetic γ-Fe₂O₃@SiO₂ nanocomposites led to the production of 6-APA/γ-Fe₂O₃@SiO₂ as a novel heterogeneous nanocatalyst. Protonation and deprotonation of 6-APA/γ-Fe₂O₃@SiO₂ nanocomposites were investigated using quantum mechanical calculations. The behaviour of bifunctionality on this catalyst was examined and the results showed that it acts as an acid–base bifunctional system, and the reaction proceeds very well under mild and ambient conditions. The deprotonation of the COOH group is easier than the NH and NH₂ groups with respect to the energy data and the results of the molecular electrostatic potential (MEP) analyses. In the presence of the nanocomposite, the protonation of the NH₂ group is more favourable than the NH group. It was characterized by powder X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive spectroscopy (EDS), vibrating sample magnetometery (VSM), thermo-gravimetric analysis (TGA), and Fourier transform infrared spectroscopy (FT-IR). This reaction is not only kinetically stable but is also a spontaneous reaction and thermodynamically favored. The superparamagnetic nanocomposite was used in the preparation of 1,4-dihydropyrano[2,3-c]pyrazole derivatives under a one-pot multicomponent reaction. The nanocomposite was recyclable for at least 10 cycles without any loss in the activity.

中文翻译：

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深入了解6-氨基青松酸结构并研究γ-Fe2O3@ SiO2核-壳纳米复合材料上酸碱位的量子力学计算，并作为多组分反应中的有效催化剂

接枝6-氨基青霉烷酸（6-APA）的超顺磁性上了γ-Fe ₂ ö ₃ @SiO _2个纳米复合材料导致生产6-APA的/γ-的Fe ₂ ö ₃ @SiO ₂作为一种新型多相纳米催化剂。质子化的去质子化和6-APA的/γ-的Fe ₂ ö ₃ @SiO _2层使用量子力学计算的纳米复合材料进行了研究。检查了该催化剂上双官能团的行为，结果表明它起酸碱双官能团的作用，在温和的环境条件下反应进行得很好。COOH基团的去质子化比NH和NH ₂容易能量数据和分子静电势（MEP）分析结果的相关分组。在纳米复合材料的存在下，NH ₂基的质子化比NH基更有利。它的特征在于粉末X射线衍射（XRD），扫描电子显微镜（SEM），透射电子显微镜（TEM），能量色散光谱（EDS），振动样品磁强（VSM），热重分析（TGA）和傅立叶变换红外光谱（FT-IR）。该反应不仅在动力学上是稳定的，而且是自发反应并且在热力学上是有利的。超顺磁性纳米复合材料用于制备1,4-二氢吡喃并[2,3- c一锅多组分反应中的]吡唑衍生物。该纳米复合材料可再循环至少10个循环，而活性没有任何损失。