Synthetic Strategies and Structural Aspects of Metal-Mediated Multi-Porphyrin Assemblies

Porphyrins play a major role as active chromophores in artificial systems mimicking the natural photoinduced processes. The formation of coordination bonds between peripheral donor sites on the porphyrins and external metal fragments has proven to be an efficient alternative to covalent synthesis for the construction of multiporphyrin assemblies, whose complexity and beauty gradu- ally approach those of the multichromophore systems found in nature. In a modular approach, relatively simple metal-mediated porphyrin adducts, owing to their thermodynamic and kinetic stability, can be exploited as building blocks in the construction of higher order architectures. Thus, multichromophore systems become accessible on demand, with a limited synthetic effort.