Supramolecular chemistry of metalloporphyrins

Supramolecular chemistry, defined as “chemistry outside a molecule”, is at the heart of the development of chemistry of complex systems, molecular devices, ensembles, and nanochemistry.1 This is the chemistry where molecules are able to self-organize, self-assemble, and self-control into systems and the components are often analogues to biological molecules. Metalloporphyrins and metallophthalocyanines are remarkable precursors in supramolecular chemistry, and the rapid development of this chemistry led to assemblies possessing various architectures and properties (photo-, electro-, and catalytic properties and others). Metalloporphyrins are one of the cornerstones on which the existence of life is based, and major biochemical, enzymatic, and photochemical functions depend on the special properties of a tetrapyrrolic macrocycle. However, metalloporphyrins are the only molecules as key elements that require assembly with other elements to form the supramolecular structure, that is, the working device. In natural systems, polypeptides define a given structural organization and hold all the moieties together. Such complex natural devices are not accessible by direct chemical synthesis so far, but their modeling, using simplified designs, has been actively exploited during the last decades. The rapid development of this new area of chemistry has promoted the understanding of the concepts of design and strategies of self-assembly of structures based on intermolecular interactions to result in natural and synthetic supramolecular complexes of metalloporphyrins. Synthetic metalloporphyrin complexes are often used as analogues of natural systems found in photosynthesis, oxygen carriers, and catalysts.2,3 Such research also led to the discovery of new applications of these systems, for example in photodynamic therapy, information storage devices or photoelectrical devices that transform energy in both directions (photocells and lightemitting diodes).4-6 An application of increasing importance is the use of metalloporphyrins as receptors, exploiting their ability to selectively form complexes which can sharply change the spectral properties.7,8 Using molecules that combine different receptor units such as porphyrins and † A.N. Frumkin Institute of Physical Chemistry and Electrochemistry. ‡ Université de Bourgogne. Irina Beletskaya was born in 1933 in Leningrad (USSR). She received her Diploma in 1955, her Ph.D. in 1958, and her Doctor of Chemistry degree in 1963, all at M.V. Lomonosov Moscow State University. The subject for the latter was “Electrophilic Substitution at Saturated Carbon”. She became a Full Professor in 1970. She is currently a head of the Laboratory of Organoelement Compounds at M.V. Lomonosov Moscow State University and a full member (Academician) of Russian Academy of Sciences. She was a recipient of the Lomonosov Prize (1979), the Mendeleev Prize (1982), and the Nesmeyanov Prize (1991). Irina Beletskaya is a chief editor of the Russian Journal of Organic Chemistry. She is the author of more than 1000 articles and a number of monographs. Her current scientific interests are focused on organoelement compounds, transition metal catalysis, and organocatalysis. Chem. Rev. 2009, 109, 1659–1713 1659