Dendrimer Porphyrins and Phthalocyanines

Some of the unique structural and functional aspects of dendrimer porphyrins in relation to the biological activities of hemoproteins and photosynthetic systems, as well as in the context of host-guest chemistry, self-assembly, materials sciences, and biomedical applications, were studied. Unique features of the step-by-step iterative synthesis of dendrimers allow porphyrin or phthalocyanine functionalities to be precisely positioned in their nanoscopic threedimensional architectures. The synthetic strategies that are used follow either a divergent or a convergent approach. Poly(aryl ester) dendrimer metalloporphyrins have been prepared convergently by the dicyclohexyl carbodiimide mediated condensation of the corresponding polyester dendrons bearing a carboxylic acid group at the focal core, with the phenolic OH groups of tetrakis(3,5-dihydroxyphenyl)porphyrin. Another type of dendrimer porphyrins includes those in which the dendritic units are attached to the pyrrole-β or axial positions of the porphyrin macrocycle.