Polystyrene-supported thiosemicarbazone-transition metal complexes: synthesis and application as heterogeneous catalysts

✍ Scribed by Sivadasan Chettiar, K; Sreekumar, K

• Publisher: John Wiley and Sons
• Year: 1999
• Tongue: English
• Weight: 83 KB
• Volume: 48
• Category: Article
• ISSN: 0959-8103
• DOI: 10.1002/(sici)1097-0126(199906)48:6<455::aid-pi166>3.0.co;2-f

✦ Synopsis

Functionalized polymers are found to be highly ef®cient in immobilizing transition metal ions. Crosslinked polystyrene supported Schiff's base complexes of metal ions such as Fe(III), Co(II), Ni(II) and Cu(II) are very effective as heterogeneous catalysts. The catalytic activity of these metal complexes has been studied in the decomposition of H 2 O 2 and in the epoxidation of cyclohexene and styrene. The reactions show a ®rst order dependence on the concentration of both the substrates and the catalyst. The in¯uence of the degree of crosslinking of the polymer support on the rate of reactions has been studied. The metal complexes show low catalytic activity at low crosslink density (2% and 5%) but 10% crosslinked resins show higher activity. A possible mechanism for the reactions is suggested.