A highly-efficient and environmental-friendly method for the preparation of Mn(III)-Salen complexes encapsulated HMS by using microwave irradiation

摘要

It was reported that the microwave-assisted in situ synthesis and encapsulation of Mn(III)-Salen complexes inside the pores of the amino-functionalized mesoporous silicas of HMS.The prepared heterogeneous Mn(III)-Salen complexes via this method were characterized by diffusion reflection UV-Vis,FT-IR,TG-DTA and N2 volumetric adsorption,and their catalytic properties were checked with the epoxidation of trans-stilbene with iodobenzene diacetate.The results indicated that,in comparison with the traditional adsorption method,the microwave-assisted approach was efficient and environmental-friendly,and could improve the loadings of Mn(III)-Salen complexes on HMS via a strengthening axial coordination of the surface's NH2 groups of HMS toward the Mn(III)-Salen complexes.Furthermore,the encapsulation of Mn(III)-Salen complexes inside the host HMS could be rapidly achieved by the HMS's porous outlets grafting a suitable molecular-size ester-terminated polyamidoester dendrimers under the microwave irradiation.As a result,the encapsulated Mn(III)-Salen complexes inside the HMS's pores showed a lower leaching,better catalytic activity and reusability than the un-encapsulated counterparts in catalyzing the epoxidation of trans-stilbene.