Metalloporphyrins solubility

Early studies of the catalytic decomposition of hydrogen peroxide have been performed with various iron(III) proto- and deuteroporphyrins, and also with metalloporphyrins soluble in organic solvents. The formation of the analogue of Cat-Cpd I has been well studied with nonaggregating iron(III) or manganese(III) sulfonated porphyrins. 

Oxo-hydroxo tautomerism as a useful tool in oxygenation reactions catalyzed by water-soluble metalloporphyrins 98CC2167. 

An interesting, pH-dependent mechanistic changeover was reported in the H2A-02-[Fem(TPPS)] (TPPS = 5,10,15,20-tetrakis(p-sulfonatophe-nyl)porphyrinate) system in aqueous solution (23). This water-soluble metalloporphyrin exists as a monomer under slightly acidic conditions and reacts with ascorbic acid on the time-scale of several hours to produce [Fen(TPPS)] in the absence of dioxygen. The formation of the [Fem(TPPS +)] radical was also reported at pH 5, but it is not clear how... 

Scheme I. Structures of sulfonated robust metalloporphyrin complexes. The axial ligand of these water-soluble metalloporphyrins depend on the pH value, at acidic pH an hydroxo ligand occupies the axial position whereas it is a water molecule at basic pH values.

In conclusion, the concept of the proximal effect is a key factor in metalloporphyrin-catalyzed reactions, not only for soluble complexes, but also for supported catalysts. 

Porphyrin-based self-assembled molecular squares 389 can form mesoporous thin films in which the edge of a square, thus the size of the cavity, can be adjusted by appropriate choice of substituents [8]. Fibers that form coil-coiled aggregates with distinct, tunable helicity are built from crown ethers bearing porphyrins 390 [9]. In addition to the porphyrin applications discussed in Sections 6.3.2.2 and 6.4, dendrimer metalloporphyrins 391 to be applied in catalysis [10] and the water-soluble dendritic iron porphyrin 319 modelling globular heme proteins [11] can be mentioned. 

Ignarro, L. J., Ballot, B., and Wood, K. S. (1984a). Regulation of soluble guanylate cyclase activity by porphyrins and metalloporphyrins.). Biol. Chem. 259, 6201-6207. 

The second and third steps involve successive additions of the pyrazine and non-surfactant water soluble metalloporphyrin complexes to the template submerged in the aqueous phase (Steps 2 and 3, respectively). The two-layered assembly is then removed from the water through a protective monolayer of stearic acid to prevent disruption of the film structure (Step 4). If instead of removing the assembly in Step 4, Steps 2 and 3 were successively repeated, multi-layered assemblies having the essential features described in Figure 1 might be realized. 

Figure 2. Representation of the dye assembly construction procedure (O-) stearic acid (-0-) surfactant metalloporphyrin (MTOAPP) and (-0-) water soluble porphyrin...

The syntheses, and especially the purification, of water-soluble porphyrin complexes are often different from the above-mentioned methods, and experimentally more difficult, because of the salt-like character of the compounds. Thus, besides the reaction conditions, some notes on the workup are given. Some papers do not specify the counter ions neutralizing the charge of the respective metalloporphyrin. In such cases, just the respective ion of the porphyrin complex is noted. The porphyrin systems involved are specified in Table 1. 

The soluble metalloporphyrin-containing polymers are formed by the copolymerization of MM A or 4-VP with macrocyclic MCM — an interaction product of acrylic acid chloride with tetra-p-aminophenylporphyrinate acetate manganese [96]. Copolymers obtained by the radical copolymerization of acryloyl derivatives of cobalt phthalocyanine with 9-vinylcarbazole [97] should also be mentioned. 

It has been shown that Gram-positive bacteria, such as Escherichia coli, are susceptible to the photosensitizing action of a variety of photosensitizers, among them amphiphilic metalloporphyrins (Pd11) [16], cationic metallophthalocyanines (Zn11) [15,17], or water-soluble derivatives of chlorophylls [18]. 

As part of the work on model heme FeNO complexes, mechanistic studies on the reversible binding of nitric oxide to metmyoglobin and water soluble Fe, Co and Fe porphyrin complexes in aqueous solution, ligand-promoted rapid NO or NO2 dissociation from Fe porphyrins, reductive nitrosylation of water-soluble iron porphyrins, activation of nitrite ions to carry out O-atom transfer by Fe porphyrins, demonstration of the role of scission of the proximal histidine-iron bond in the activation of soluble guanylyl cyclase through metalloporphyrin substitution studies, reactions of peroxynitrite with iron porphyrins, and the first observation of photoinduced nitrosyl linkage isomers of FeNO heme complexes have been reported. 

Polymers can be used to locate reagents at particular sites and to provide unique surface environments. The possible applications of functionalized polymers in solar energy storage systems have been reviewed in detail. Metalloporphyrins or bipyjRu " " can be attached to various water-soluble polymers via covalent or electrostatic linkages. The ability of the dye to photoreduce dissolved in the aqueous phase, depends strongly upon... 

Radiative and Nonradiative Decay Processes - Due to the potential application of these compounds as photosensitizers for photodynamic therapy" the photophysical properties of porphyrins and phthalocyanines, and their corresponding metal complexes, have been investigated extensively over the past decade. The photophysical properties of water-soluble metalloporphyrins, and especially the tetraphenylsulfonates," have been re-examined but nothing new has been found. The disulfonated metallophthalocyanines (MPcS2, where M = Al ", Ga" , or Zn") form complexes with fluoride ions for which the fluorescence yields and lifetimes are decreased with respect to the parent dyes while there are... 

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