Rafiee Ezzat, Rahpeima Nasibeh, Eavani Sara
Acta Chim Slov. 2014;61(1):177-84.
12-Tungstophosphoric acid supported on silica-coated magnetic nano particles was prepared and characterized by transmission electron microscopy, scanning electron microscopy, powder X-ray diffraction and inductively coupled plasma atomic emission spectroscopy. Acidity of the catalysts was measured by potentiometric titration with n-butylamine. Catalytic activity of the prepared sample was evaluated in the model synthesis of 1,2-disubstituted benzimidazole derivatives in water. The catalyst showed excellent catalytic activity and the corresponding products were obtained in good to excellent yields under mild reaction conditions. Furthermore, the catalyst could be easily recovered using an external magnet and reused several times. The leaching and surface acidity of the recovered catalyst were also investigated.
制备了负载在二氧化硅包覆磁性纳米颗粒上的12-钨磷酸，并通过透射电子显微镜、扫描电子显微镜、粉末X射线衍射和电感耦合等离子体原子发射光谱对其进行了表征。用正丁胺电位滴定法测定催化剂的酸度。在水相中1,2-二取代苯并咪唑衍生物的模型合成中评估了所制备样品的催化活性。该催化剂表现出优异的催化活性，在温和的反应条件下，相应产物的收率良好至优异。此外，该催化剂可以很容易地用外部磁铁回收并重复使用几次。还研究了回收催化剂的浸出和表面酸度。
