Discrete supramolecular assemblies of porphyrins mediated by coordination compounds

Metal-driven self-assembly has emerged as a viable alternative to covalent synthesis in the construction of large and sophisticated multi-porphyrin architectures, whose complexity and function begin to approach the properties of naturally occurring systems. The design and preparation of robust and shape-persistent discrete assemblies, obtained by coordination of meso-pyridylporphyrins to ruthenium, palladium and zinc centers, is comprehensively discussed in this micro-review, that covers research in this field carried out by the authors at the University of Trieste in the last few years. NMR spectroscopy and X-ray crystallography were used jointly for the unambiguous characterization of the new species in solution and solid state, respectively. Very often the adducts of nanoscopic dimensions, in which the number, position, relative distance and orientation of the chromophores is well defined, were obtained through hierarchical supramolecular self-assembly: multi-porphyrin components were used as building blocks for the metal-mediated assembly of more elaborate architectures. ((C) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003).