Immobilization of homogeneous catalysts on various solid supports with the advantage of catalysts separation and recycling is one strategy that developed in recent years [1]. Porous magnetic nanocomposites has been employed as useful and versatile solid support for homogeneous catalyst immobilization. These materials owing to its high thermal stability, high pore volume, high surface area, very narrow pore size distribution , and chemical and mechanical stability, are ideal to use as support[2]. Tetrazoles are one of the important and useful class of nitrogen-rich compounds that contain a wide range of applications, in the fields of catalysis technology, material sciences, organic synthesis, information recording systems, coordination chemistry, explosives, and especially in the synthesis of N-containing heterocycles[2-4]. In the present study, we prepared Schiff-base complexes of nickel anchored to magnetic nanoporous MCM-41 as a highly efficient and recoverable nanocatalyst for the synthesis of 5- substituted 1H-tetrazoles in PEG as green solvent. The catalyst was characterized by FT-IR spectroscopy, TGA, XRD, VSM, TEM, SEM and ICP-OES techniques The notable advantages of this procedure are simplicity in operation, mild reaction conditions, use of cheap and chemically stabile oxidant, short reaction times, and high yields of products. Also the catalyst can be easily separated from the reaction mixture by external magnet and reused several times without any significant loss of catalytic stability and activity.
