Metalloporphyrins assembly

This work is also notable in that Cole et al. performed detailed aggregation studies of the heme MPPIX using UV-vis and fluorescence spectroscopies to detect the formation of 71-71 hetero-metalloporphyrin assemblies under assay conditions. By employing UV-vis absorbance spectroscopy, the aggregation of porphyrin and metalloporphyrin systems may be examined. The in vitro assay system used for hemozoin... 

Luminescence and Photoelectrochemistry of Surfactant Metalloporphyrin Assemblies on Solid Supports... 

Brumbadi, M.T., Boal, A.K., and Wheeler, D.R. (2009) Metalloporphyrin assemblies on pyridine-functionalized titanium dioxide. Langmuir, 18, 10685-10690. 

Diskin-Posner, Y. Patra. G.K. Goldberg. I. Crystal engineering of metalloporphyrin assemblies. New supramolecular architectures mediated by bipyridyl ligands. Chem. Commun. 2002. 1420-1421. 

The principle for construction of aggregates ba.sed on these features is. schematically represented in Figure 11. Here tme oligomerization processes such as dimerization, trimerization and so on are considered, because the metalloporphyrins assemble with themselves contrary to what will be described in other sections of this chapter, no additional ligand or metal is required for the assembly... 

Sakamoto, M., A. Ueno, and H. Mihara (2001). Multipeptide-metalloporphyrin assembly on a dendrimer template and photoinduced electron transfer based on the dendrimer structure. Chem. Eur. J. 7(11), 2449-2458. 

Most studies of ORR catalysis by metalloporphyrins have been carried out using water-insoluble catalysts absorbed on a graphite electrode in contact with aqueous solution. In a limited number of cases, four other approaches have been used catalysts imbedded in an inert film (i.e., Nafion or lipid) on the electrode surface self-assembled monolayers of catalysts catalysts in aqueous or mixed organic/aqueous solutions in contact with an electrode and catalysis in mixed aqueous/organic medium using... 

Relatively little work has been done on ORR catalysis by self-assembled mono-layers (SAMs) of metalloporphyrins. The advantages of this approach include a much better defined morphology, structure, and composition of the catalytic film, and the surface coverage, and the capacity to control the rate at which the electrons ate transferred from the electrode to the catalysts [CoUman et al., 2007b Hutchison et al., 1993]. These attributes are important for deriving the catal5d ic mechatfism. The use of optically transparent electrodes aUows characterization of the chemical... 

Fig. 3. A trivial closed trimer assembled on a six-coordinate metalloporphyrin.

Sanders (14) has exploited the strong and selective coordination of phosphine donor groups to Ru(II) to construct hetero-dimetallic porphyrin dimers (17, Fig. 5). An alkyne-phosphine moiety introduced on the periphery of a free base or metalloporphyrin (M = Zn or Ni) spontaneously coordinates to a Ru(II)(CO) porphyrin when the two porphyrins are mixed in a 1 1 ratio. Coordination is characterized by a downfield shift of the 31P resonance (A<531P = 19 ppm). There is no evidence of self-coordination of the zinc porphyrin at 10 6 m in toluene, there is no shift in the Soret band in the UV-Vis absorption spectrum. The Ni-Ru dimer was observed by MALDI-TOF mass spectrometry. Heating the Ru(II)CO porphyrin with 2 equivalents of the phosphine porphyrins led to quantitative formation of trimeric assemblies. 

The axial coordination of metalloporphyrins to a pyridyl ligand was successfully exploited by two groups to produce porphyrin-stoppered rotaxanes. Sanders (48) assembled a rotaxane by simply mixing the constituent parts. Zn(II), Ru(II)CO, and Rh(II)Cl porphyrins were used as stoppers. Branda (49) reported the stoppering of a pseudorotaxane by adding two equivalents of a Ru(II)CO porphyrin that coordinated to... 

When the metalloporphyrin bears a donor group on its periphery, it can behave as a self-complementary ditopic unit capable of metal-ligand induced dimerization. Many systems have been synthesized using different metals, ligands, and spacers. The length and geometry of the spacer groups determine the stoichiometry of the assembly process. 

Bouamaied I, Coskun T, Stulz E (2006) Axial Coordination to Metalloporphyrins Leading to Multinuclear Assemblies 121 1-47 Boulanger AM, see NoletMC (2004) 107 145-158... 

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