Ionically bound metalloporphyrin pairs on solid polymer support

Abstract

The present work demonstrates a simple and elegant strategy by which synthetically simple porphyrins are grafted on solid polymer support to generate porphyrin pairs held together by strong coulombic forces. Metalloporphyrins of tetra(4-pyridyl)porphyrins (MTPyP) were reacted with chloromethylated polystyrene (PS) beads to get covalently bound monocationic porphyrins on the polymer support (PS–MTPyP+). These were then converted to their tetracationic species (PS–MTMe3PyP4+) by exhaustive quaternisation, using CH 3 I . These polymer-grafted cationic porphyrins were made to react with tetraanionic p-sulphonated phenylporphyrins (MTPPS4-) in aqueous conditions. Analysis showed that the PS–MTMe3PyP4+ take up MTPPS4- in exactly 1:1 stoichiometry to form strongly bound (ionically) porphyrin pairs. A variety of homo- and hetero-porphyrin pairs involving central metal ions like Mn , Co , Cu , Zn and Ag and also free-base porphyrins are generated by this strategy.