Kamali Ehsan, Dreekvandy Fahim, Mohammadkhani Abolfazl, Heydari Akbar
Chemistry Department, Tarbiat Modares University, PO Box: 14155-4838, Tehran, Iran.
BMC Chem. 2024 Apr 20;18(1):78. doi: 10.1186/s13065-024-01176-5.
In this study, novel nanomagnetic catalysts, namely FeO-MgO@choline formate (Ch. F.) and FeO-MgO@choline cyanide (Ch. CN), were synthesized through immobilizing choline-based ion liquids to magnetic support via a simple and cost-effective methodology. FT-IR, TGA, FE-SEM, VSM, EDS, BET, and XRD techniques were employed to assess and characterize these organic-inorganic compounds. Following the successful preparation of nanoparticles, the catalysts were utilized in Knoevenagel and benzoin condensations. FeO-MgO@Ch.F. exhibited exceptional activity in Knoevenagel condensation under solvent-free conditions at room temperature, achieving high yields (91-98%) in a short timeframe. Similarly, FeO-MgO@Ch.CN demonstrated remarkable activity in benzoin condensation under environmentally friendly solvent conditions, yielding higher isolated yields (76-88%). Furthermore, these magnetically recyclable multifunctional catalysts displayed the ability to be reused up to five times without a significant loss in efficiency. Additionally, the heterogeneity of this nanocatalyst was investigated using the hot filtration technique. The findings indicated that the reaction primarily occurs via a heterogeneous pathway.
在本研究中，通过一种简单且经济高效的方法，将胆碱基离子液体固定在磁性载体上，合成了新型纳米磁性催化剂，即FeO-MgO@甲酸胆碱（Ch.F.）和FeO-MgO@氰化胆碱（Ch.CN）。采用傅里叶变换红外光谱（FT-IR）、热重分析（TGA）、场发射扫描电子显微镜（FE-SEM）、振动样品磁强计（VSM）、能谱分析（EDS）、比表面积分析（BET）和X射线衍射（XRD）技术对这些有机-无机化合物进行评估和表征。在成功制备纳米颗粒后，将催化剂用于Knoevenagel缩合反应和安息香缩合反应。FeO-MgO@Ch.F.在室温无溶剂条件下的Knoevenagel缩合反应中表现出优异的活性，在短时间内实现了高产率（91-98%）。同样，FeO-MgO@Ch.CN在环境友好的溶剂条件下的安息香缩合反应中表现出显著的活性，分离产率更高（76-88%）。此外，这些可磁回收的多功能催化剂能够重复使用多达五次，而效率没有显著损失。此外，使用热过滤技术研究了这种纳米催化剂的非均相性。研究结果表明，该反应主要通过非均相途径进行。
