Preparation and Catalytic Oxidizing Potential of Polymer Supported Chelating Amine and Schiff Base Complexes

Article abstract of DOI:10.1021/ja00523a021

A new, versatile, high-yield synthesis for covalently attaching multidentate chelates to polystyrene is described.Polymeric substrates containing bound polydentate amines as discrete units can be obtained by reacting chloromethylated polystyrene with bis(2-cyanoethyl)amine, followed by BH3/THF reduction, to provide polymer-attached bis(3-aminopropyl)amine, (*)-DPT.These materials form the basis for the preparation of a wide variety of chelating ligands, for example, through the Schiff base reaction with various aldehydes and ketones.In order to demonstrate the feasibility of these polymer reactions, the entire sequence of reactions was carried out in solution using benzyl chloride as the starting material.A series of polymer-bound metal complexes were prepared and characterized.ESR spectra of the polymer-bound Cu^IISalDPT and Co^IISalDPT*O2 complexes were very similar to their respective frozen glass spectra.The Moessbauer spectrum of the polymer-bound Fe^IISalDPT was similar to the powder spectrum.The Fe(II)-bound complex was irreversibly oxidized upon exposure to air.The Co^IISalDPT-bound complex was found to be an active catalyst for the oxidation of 2,6-dimethylphenol.A large enhancement in product selectivity is obtained with the polymer Co(II) complex over the solution analogue.