SYNTHESIS AND CHARACTERIZATION OF HYBRID PORPHYRIN DIMERS AND HALOGENATED PORPHYRIN DIMERS

Zinc hybrid porphyrin dimer(ZnTTP-C-2-H2PFPP, ZnTTP-C-2-H2TTP, ZnPFPP- C-2-H2PFPP, and ZnPFPP-C-2-H2TTP) and manganese (III) halogenated porp hyrin dimers (MnPFPP-C-2-MnPFPP, MnPFPP-C-2-MnDCPP, and MnDCPP-C-2-MnD CPP) covalently bridged by an ethylene moiety (Scheme 1) were synthesi zed and characterized by UV-vis spectra, fluorescence spectra, and cyc lic voltammograms. These porphyrin dimers could be embedded into the l ipid bilayers of a liposomal membrane. The redox potential of the mang anese complex for the halogenated porphyrin dimers increased with incr easing of halogen portions on the porphyrin rings. An efficient energy transfer of the excited singlet state in the covalently-linked zinc h ybrid dimers from zinc porphyrin to a free base porphyrin was observed , depending on the porphyrin structure. Furthermore, the manganese hal ogenated porphyrin dimers acted as catalysts of transmembrane electron transfer; such activity depends on the steric effect of halogen porti ons on the porphyrin ring.