Micellar aggregates of platinum(II) complexes containing porphyrins

The complex [Pt(Cy2dim)Me]4(TpyP)(CF3SO3)4 (1) (Cy2dim=dicyclohexyldiimine; TpyP=5,10,15,20-tetrakis(4-pyridyl)-21H,23H-porphine) has been synthesized and characterized with a number of spectroscopic techniques. The solubilization of 1 in anionic (sodium dodecyl sulfate, SDS) and neutral (Triton X-100, TX-100) aqueous surfactant solutions has revealed two different modes of interaction: (i) aggregation in the hydrophobic region of SDS micelles; and (ii) aggregation in the hydrophobic region with partial intercalation in the solvent accessible area of TX-100 micelles. In the case of SDS, the formation of premicellar aggregates has been evidenced by a surfactant concentration range two orders of magnitude lower than the critical micellar concentration (cmc). The metalated Mn(III)TpyP derivative of complex 1 exhibits a moderate peroxidase activity in agreement with the aggregation models proposed for the micellar solutions.