Phthalocyanine iron compound

The reduced alkyl complexes are reoxidized by O2 to the iron(lll) alkyls. The corresponding diamagnetic phthalocyanine iron(ll) alkyl complexes, rFe(Pc)R), were prepared by two-electron reduction of Fe(Pc) by LiAIFl4 to give [Fe(Pc) (actually the Fe(I) phthalocyanine radical anion) followed by reaction with Mel, Etl or i-PrBr. The methyl compound, [Fe(Pc)CHi] was characterized by X-ray crystallography. ... 

Finally, phthalocyanine iron catalysts were also used for the oxidation of alcohols to yield corresponding carbonyl compounds with nonbenign hypervalent iodine oxidants [147]. 

PHTHALOCYANINE COMPOUNDS. Phthalocyanine. C32HISN8, compounds have found widespread acceptance in a variety of applications. The discovery of iron phthalocyanine and Ihe elucidation of ics structure led to the commercial application of copper phthalocyanine. 

A variety of different metal complexes have been screened as catalysts for allylic amination using phenyl hydroxylamine 108 as the nitrogen fragment donor, and it was found that iron-complexes have better redox capacity compared to molybdenum [64]. With the iron compounds, higher yields and a lower amount of hydroxylamine-derived byproducts are obtained. These byproducts constitute one of the problems in this type of allylic amination reactions in general, as their formation is difficult to suppress. The allylic amination reaction of a-methyl styrene 112 with 108 can, e.g., be catalyzed by the molybdenum dioxo complex 107, iron phthalocyanine 114, or by the combination of the iron chlorides 115 [64,65]. It appears from the results in... 

Models which allow interpretation of X-ray diffraction data in terms of orbital populations, radial dependence of the orbitals and LCAO coefficients are discussed. They are applied to experimental data on iron(II) phthalocyanine, iron(II) meso-tetraphenylporphyrin and its bis-pyridyl and bis-tetrahydrofurane derivatives. The diffraction studies indicate that the first two complexes are intermediate spin complexes with differing ground states while the last two are respectively low- and high-spin iron(II) compounds. A difference between the two intermediate spin complexes is thought to be related to the effect of the crystalline environment. This interpretation implies that the leading contributor to the ground... 

Non-fused iron catalysts have been studied earlier. The famous Uhde catalyst was KAl (Fe(CN)6), which was used, to be applied in industry. It was abandoned because of its poor stability, and up to now there are still reports about its modifications. Intermetallic compound and alloy catalysts, such as LaNij, FeTi, Fe2Ce and FeZr etc., were also expected to be prospective, but until now they have not been put into practice. In 1970s, the well-known electron donor-acceptor (EDA) catalysts, e.g., phthalocyanine iron-alkali metal, molysite — graphite — potassium and ferrocene-activated carbon-potassium catalyst systems, were found to have the ability to synthesize ammonia under mild conditions in the laboratory. Unfortunately, their activities declined rapidly in the experiments of scale-up. The application of EDA catalysts in industry turned to be a visionary. Therefore, replacement of fused iron catalyst is not an easy thing for a very long time. 

Like the porphyrins, phthalocyanine is capable of forming metal complexes, a number of which have been studied and certain of which bear striking similarities of function to porphyrin compounds. For example, the iron compound shows oxidase and peroxidase effects characteristic of the hemes (32). 

In /<-oxo dimers two phthalocyanines are bridged by an oxygen atom. Iron phthalocyanines, especially, tend to form this kind of compound, e.g. 13. 

Iron in the oxidation state + III in dimeric p-oxo compounds 5 can be reduced to iron + II, leading to monomeric phthalocyanines 6.351... 

A practical method of modification of polysaccharides by clean oxidation using H2O2 as oxidant and cheap iron phthalocyanine as catalyst has been developed. Since no acids, bases or buffers and no chlorinated compounds were used, a pure product can be recovered without additional treatment. Importantly, this flexible method provides materials with a wide range of DScho and DScooh just by an appropriate choice of the reaction conditions. Oxidized polysaccharides thus obtained possess various, tailormade hydrophihc/hydrophobic properties which have been tested successfully in cosmetic and other apphcations. 

Transition metal compounds, such as organic macrocycles, are known to be good electrocatalysts for oxygen reduction. Furthermore, they are inactive for alcohol oxidation. Different phthalocyanines and porphyrins of iron and cobalt were thus dispersed in an electron-conducting polymer (polyaniline, polypyrrole) acting as a conducting matrix, either in the form of a tetrasulfonated counter anion or linked to... 

Other photosensitisers in clinical or pre-clinical trials include zinc phthalocya-nine, aluminium sulphonated phthalocyanines, benzoporphyrins, benzochlorins and purpurin-lS-iV-alkylamides, all of which absorb strongly in the 675-700 nm region. An alternative approach to the photosensitisation in PDT involves the use of 5-aminolaevulinic acid (ALA). This compound itself is not a sensitiser but in human cells it is the key metabolic precursor in the biosynthesis of protoporphyrin IX, which can act as a photosensitiser. Normally the biosynthetic process would continue beyond protoporphyrin IX to the iron containing haem. However, by adding extra ALA and iron chelators, the ferrochelatase action is inhibited and the normal feedback mechanism by-passed resulting in a build up of protoporphyrin IX in the cell. The mechanism is illustrated in Figure 4.24. ... 

In solution the photochromism of coordination compounds can result from photoinduced isomerization (e.g. metal dithizonates186-188), substitution (e.g. iron(II) phthalocyanine in the presence of benzyl isocyanide189) and oxidation—reduction (e.g. tris(diethyldithiocarbamato)-nickel(IV) bromide190). 

---