ABSTRACT
The symmetric palladium(II)(4-OH)2salen complex ((4-OH)2salen=N,N’-bis(4-hydroxysalicylidene)ethylenediimine) has been immobilised on MCM-41, resulting in an efficient and highly recyclable heterogeneous catalyst for the Suzuki-Miyaura reaction. The catalyst afforded a fast and high percent conversion of bromobenzene at a catalyst loading of 0.05 g, 0.184 mol% Pd. Transmission electron micrographs (TEM) and surface area measurements clearly demonstrate that the immobilisation of the Pd(II)(4-OH)2salen complex on mesoporous silica has a significant effect on the pore structure of the catalyst. Nevertheless, after immobilisation of the palladium complex, the mesoporosity of the material is retained, as evidenced by nitrogen sorption measurements. The scanning electron microscope (SEM) images show that both MCM-41 and the MCMSalenPd catalyst have similar types of external surface morphology; however, the catalyst was less ordered.
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