Supramolecular porphyrins

Aiaki K, Toma HE. 2006. Supramolecular porphyrins as electrocatalysts. In Zagal JH, Bedioui F, Dodelet J-P, editors. N4-Macrocyclic Metal Complexes. New York Springer, p. 255. 

Schneider, H. J., Tianjun, L., Sirish, M., and Malinovski, V. (2002) Dispersive interactions in supramolecular porphyrin complexes, Tetrahedron 58, 779-786. 

Satake A, Kobuke Y. Dynamic supramolecular porphyrin systems. Tetrahedron 2005 61 13-41. 

Hunter C. A. and Hyde R. K. Photoinduced Energy and Electron Transfer in Supramolecular Porphyrin Assemblies. Angew. Chem., Int. Ed. Engl. 35 (1996) pp. 1936-1939. 

E. Multielectron-Transfer Catalysis by Supramolecular Porphyrin Films / 427... 

Figure 12. Supramolecular porphyrins obtained by coordination of transition metal complexes to the periphery of the macrocyclic ring (a similar scheme can be extended to the 3-TPyP and analogous porphyrazine species), [dmso = dimethyl sulfoxide (ligand), form = A,A-9-di- -tolyformamidinate, and TFA = trifluoroacetate.l...

The porphyrin reduction potential is also sensitive to the coordinated metal ion and its oxidation state. For example, the reduction of the Co 4-TRPyP) species is cathodically shifted due to the previous formation of Co (4-TRPyP), while the ring oxidation potentials remain almost invariant at 1.5 V. Although the existence of the M P state was already reported for Ni, Co, and Fe porphyrins, the only case detected in supramolecular porphyrins is for Co (4-TRPyP) and Co (4-TCPyP), occurring around — I.IV, as observed in the spectroelectrochemistry measurements (122, 170). Its formation usually shifts the porphyrin and bpy reduction processes to more negative potentials (Table III). In all cases, the spectroelectrochemistry technique has proved essential for the proper assignment of the redox processes (a typical set is shown in Fig. 18) (38, 118, 119, 170). 

The capability of the supramolecular porphyrins to induce photodamage to calf thymus DNA and supercoiled pBR322 also was evaluated (168). The irradiation of the last one in the presence of 1.5 )J,M H2(4-TRPyP) solution led to efficient nicking and formation of the open circular species, as well as to an increase of the amount of oxidized deoxiguanosine (8-oxodGuo). Similar results were obtained for calf thymus DNA (169). 

It was observed that the direct electrodeposition of H2(ETRPyP) from a DMF solution leads to poor quality films, due to the looseness of the presumably low molecular weight polymeric chains. Considering that the supramolecular porphyrin is able to form quite homogeneous films by dip coating (122, 167, 170, 184, 250, 286, 296) and that such films are poorly soluble in acetonitrile, an altenative procedure was devised. This procedure was carried out by an electropolymerization reaction on pre-formed films (53, 172), whose advantages are the high concentration of the monomer on the electrode surface and the presence of suitably preoriented molecules, which keep the n-stacking structure of the dip-coated films. Such characteristics increase the efficiency of the electropolymerization, since only one or two scans in the... 

Another important application of the supramolecular porphyrin films is in the determination of drugs (e.g., acetaminophen in pharmaceutical formulations). This work was recently performed (287) by means of batch injection analysis (BIA) utilizing amperometric detection with glassy carbon electrodes modified with [Co (4-TRPyP)](CF3S03)5 films. 

K. Ogawa, Y. Kobuke, Formation of a Giant Supramolecular Porphyrin Array by Self-Coordination , Angew. Chem. Int. Ed., 39,4070 (2000)... 

Hunter and Hyde have described a new approach for the construction of supramolecular porphyrin assemblies which uses a co-operative co-ordination interaction to generate self-assembled chromophore arrays, and the presence of... 

Fig. 24 a STM image showing Cgo guests in the pits of a template created from a porphyrin derivate on Ag( 111) and b proposed molecular model of a Ceo molecule hosted inside a supramolecular porphyrin-based pore (from [201])... 

This chapter focuses on supramolecular porphyrin systems that are stable enough to be characterized in solution. Assemblies coordinated only in solids (e.g., crystals) will not be included. In order to maintain these supramolecular structures in solution, strong complementarity and multitopic coordinations are required, rather than a simple monotopic axial coordination. Of these conditions, this discussion will be concerned only with those necessary for the complementary coordinations, and with the presentation of various examples of these coordinations. The issue of multitopic coordination will be dealt with in another forum. Self-complementary coordination can be used to obtain dimers, rings, and one- and two-dimensional arrays. These supramolecular systems should not only influence structure formation, however, but also be closely related to their functions. It is therefore natural to discuss the... 

Keywords Rhenium Molecular square - Supramolecular Porphyrin... 

Another type of catalytic system being developed involves the tethering of a catalytically active metal center to the cavity of a supramolecular porphyrin square. In this example, the square cavity serves as a protective barrier that significantly lengthens catalyst lifetime. 

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