Metal porphyrins, applications

Iodosylbenzene has been extensively utilized over the last few years for its ability to cleanly transfer oxene oxygen atoms to metals and possibly generate high-valent reactive metal-oxo species. PhIO has been successfully used instead of 02+NADPH in conjunction with cytochrome P-450 to hydroxylate alkanes,81 and has found a variety of interesting applications as a two-electron oxidant in the presence of first-row transition metal porphyrins. 

Further Chemical Reactions of Noble Metal Porphyrins Notes on Electrochemistry, Catalysis, and Other Applications... 

The advantage of coordinative bonds in metal porjAyrins is the easy preparation including high formation constants. But the complex stability was not yet reported in the literature. It was observed that the complex of Fe(II)-protoporphyrindimethylester (7c) with poly(l-vinylimidazole-co-styrene) is easily separated from the starting material by reprecitating a benzene solution twice in methanol". So a pocket like that in globin is not observed until now. In contrast with a covalent bond in metal porphyrins no separation can occur. Therefore the application for coordinative bonds in metal porphyrins is limited to unchanged solutions or solids. 

The macrocycle phthalocyanine contains 8 N atoms, but usually only the four N-atoms on the inner side of the cycle are able to coordinate. In fact, in most cases the synthesis of phthalocyanine is realized in the presence of a metal ion as the template. It is also possible to attach various substituents on the phthalocyanine macrocycle. As for porphyrin, when coordinating to a metal ion, the H-atoms of the two NH groups on the inner side of the phthalocyanine cycle are replaced. The incorporation of metal porphyrin and phthalocyanine complexes into porous crystals has been gaining increasing interest. The properties of the complexes located in zeolite channels or cages are usually different from those of the compounds in solution, and they may find applications in areas such as catalysis, photochemistry, electrochemistry, and biomimetics. 

What kind of information is drawn from the vibrational spectrum This is the most important question for the practical application of vibrational spectroscopy in the study of metalloporphyrins. Indeed, apart from the vibrational assignments, a great deal of experimental data have been accumulated to establish some empirical rules of the IR and RR spectral features with regard to the coordination number, the spin- and oxidation-states, and the core-size of metal-porphyrins (i.e. the center to pyrrole nitrogen distances). Such empirical rules are summarized here. 

Other on-line detectors receive rare mention in the literature and are used for specialty applications. Nickel and vanadium detectors have been used to detect the distribution of metal porphyrins in asphalts (111). Fluorescence detectors have been used to detect cut points between associated and nonassociated constituents. 

Schilling, T., Okimola, A, Masa, J., Schuhmann, W, and Bron, M. (2010) Carbon nanotubes modified with elec-trodeposited metal porphyrins and phenanthrolines for electrocatalytic applications. Electrochim. Acta, 55 (26), 2S92-ie02. 

Because of limited space, this chapter covers porphyrins and expanded porphyrins as receptors through mostly non-covalent or supramolecular interactions. As a general rule, examples wherein the porphyrin acts as a receptor via metal coordination are excluded. For a further reading on this latter topic, the reader is referred to a recent Chemistry Review article entitled Supramolecular Chemistry of Metallopor-phyrins. On the other hand, inspired by a recent review by Anslyn entitled Supramolecular Analytical Chemistry, we expand our definition of receptor-substrate interactions to include certain boronic acid binding motifs and several representative examples of metalated porphyrins that are applied to sensing applications, wherein the proposed mode involves metal complexation. Thus, included in this chapter is a brief summary of the seminal work carried out by Suslick and his group, where porphyrins are used to create the so-called artificial nose, that is, an array-based sensing device for various vapors. Also included are... 

While not a focus of this chapter per se, metalated porphyrins have a near unique ability to coordinate guests in the open axial positions, which produces what is often a ligand-specific spectral shift. This makes metalloporphyrins appealing as sensors. Recently, considerable effort has been made to exploit this trait, and some of the ground-breaking works in an application sense has been done by the Suslick group. These researchers specialize in making arrays, ... 

Some general reviews relating to the chemistry of Ru/Os-r hydrocarbon complexes appear in the literature the reactivity of Ru-H bonds with alkenes and alkynes/ aspects of ruthenium/osmium vinylidene/allenylidene/cumul-enylidene complexes,equilibria of M-R/M=CR2/M=CR complexes, the organometallic chemistry of metal porphyrin complexes, and the reactions of [Os(P Pr3)2(CO)HGl], ruthenium pyrazoly I borate complexes,and metallabenzynes. Other reviews relate more to applications of some of the complexes outlined in this chapter. See, for example, metal vinylidenes in catalysis,the development of Grubbs-type alkene metathesis catalysts, applications of ruthenium/osmium carbene complexes in metathesis polymerization, and the role of Ru /V-hetero-cyclic carbene complexes in metathesis polymerization. ... 

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