Metal complexes of phthalocyanine

This paper describes studies in which phthalocyanine and metal complexes of phthalocyanine were sublimed onto the surfaces of... 

Hock and Kropf compared the catalytic activities of different metal complexes of phthalocyanine for the oxidation of cumene, and their results are recorded in Table 3. 

Boucher, L. J. "Metal Complexes of Phthalocyanines" in Coordination Chemistry of Macrocyclic Compounds G. A. 

Transition metal complexes of phthalocyanine encaged in faujasite type zeolites have been reported as efficient catalysts in the oxidation of alkanes at room temperature and atmospheric pressure [6-13]. These catalysts constitute potential inorganic mimics of remarkable enzymes such as monooxygenase cytochrome P-450 which displays the ultimate in substrate selectivity. In these enzymes the active site is the metal ion and the protein orientates the incoming substrate relative to the active metal center. Zeolites can be used as host lattices of metal complexes [14, 15]. The cavities of the aluminosilicate framework can replace the protein terciary structure of natural enzymes, thus sieving and orientating the substrate in its approach to the active site. Such catalysts are constructed by the so-called ship in a bottle synthesis the metal phthalocyanine complexes are synthesized in situ within the supercages of the zeolite... 

These systems and several other were later re-investigated by Usol tseva through intensive research, mainly on metal complexes of phthalocyanines (320) and porphyrins ((321), (322) (Tables 84 and 85)1200-1204 understand the influence of structural modifications... 

Behavior of metal complexes of phthalocyanines in supramolecular systems with TX-lOO (Fig. 13.8) is very different from other systems of micellar carriers. Tetra-substituted ZrL Pc, as in other supramolecular systems, has an absorption band with a wavelength of 678 nm corresponding to monomeric of molecules in the micelles. In micellar solutions of SiCl Pc absorption maximum at wavelength of 676 nm is observed only, indicating a completely isolated metal complex in this conditions. Unlike other systems, V=OPc has a well-defined absorption band at 678 mn, which corresponds to the presence of monomers in the system, the band bathochromic shifted to 830 nm, which corresponds to J-aggregates and the absorption band hypsochromic shifted to 630 nm, which corresponds to H-aggregates. Hence, V=OPc molecules interaction with TX-lOO micelles form three different type aggregation states of the molecules. 

The simple porphyrin category includes macrocycles that are accessible synthetically in one or few steps and are often available commercially. In such metallopor-phyrins, one or both axial coordinahon sites of the metal are occupied by ligands whose identity is often unknown and cannot be controlled, which complicates mechanistic interpretation of the electrocatalytic results. Metal complexes of simple porphyrins and porphyrinoids (phthalocyanines, corroles, etc.) have been studied extensively as electrocatalysts for the ORR since the inihal report by Jasinsky on catalysis of O2 reduction in 25% KOH by Co phthalocyanine [Jasinsky, 1964]. Complexes of all hrst-row transition metals and many from the second and third rows have been examined for ORR catalysis. Of aU simple metalloporphyrins, Ir(OEP) (OEP = octaethylporphyrin Fig. 18.9) appears to be the best catalyst, but it has been little studied and its catalytic behavior appears to be quite distinct from that other metaUoporphyrins [CoUman et al., 1994]. Among the first-row transition metals, Fe and Co porphyrins appear to be most active, followed by Mn [Deronzier and Moutet, 2003] and Cr. Because of the importance of hemes in aerobic metabolism, the mechanism of ORR catalysis by Fe porphyrins is probably understood best among all metalloporphyrin catalysts. 

The seiectivities of metal complexes of cofacial porphyrinoids (porphyrins, corroles, and phthalocyanines) reported in the literature by mid-2007 are summarized in Fig. 18.15. The data are organized by the type of catalyst as well as in order of decreasing Mav Whereas ORR catalysis by certain cofacial porphyrins, such as (FTF4)Co2 and (DPY)Co2 (Y = a, B) has been smdied extensively by a number of groups, and the values of av are known with high degree of confidence, those for most other catalysts... 

Vasudevan P, Santosh, Mann N, Tyagi S. 1990. Transition metal complexes of porphyrins and phthalocyanines as electiocatalysts for dioxygen reduction. Transition Metal Chemistry, 15, 81-90. 

For systemic administration, the photosensitizer usually has to be delivered into the bloodstream by intravenous injection. Since the photosensitizer is a solid, this means that a solution or a stable suspension has to be provided. Metal complexes of the basic porphyrin and phthalocyanine nuclei are insoluble in water, so that some effort has to be made to render the system water soluble, or at least amphiphilic, by placing various substituents (e.g., S03H, C02H, OH, NR3+, polyether, aminoacid, sugar) on the periphery of the molecule. The aromatic character of the ligand offers a suitable opportunity for such substitutions to be made. Examples will appear frequently in the following sections. 

Other sensors are mostly grouped towards the triethylamine. In the case of porphyrins 6-8, 13 the coordinated metal is no longer able to drive the selectivity pattern and the presence of the peripheral alkyl chains completely shadows the coordination interactions. This result can explain the failure to observe the coordination interaction in the sensing mechanism of the metal complexes of the closely related alkyl chains functionalized phthalocyanines reported in the past by Gopel and coworkers [22]. 

Coordination compounds composed of tetrapyrrole macrocyclic ligands encompassing a large metal ion in a sandwich-like fashion have been known since 1936 when Linstead and co-workers (67) reported the first synthesis of Sn(IV) bis(phthalocyanine). Numerous homoleptic and heteroleptic sandwich-type or double-decker metal complexes with phthalocyanines (68-70) and porphyrins (71-75) have been studied and structurally characterized. The electrochromic properties of the lanthanide pc sandwich complexes (76) have been investigated and the stable radical bis(phthalocyaninato)lutetium has been found to be the first example of an intrinsic molecular semiconductor (77). In contrast to the wealth of literature describing porphyrin and pc sandwich complexes, re-... 

Phthalocyanine (59) and naphthalocyanine (60) complexes appear to be highly active, and Zn-60 adducts have attracted commercial interest (259, 260). Many metal complexes of 56, 59 and 60 are very... 

The importance of phthalocyanines, apart from their early use as models for hemes and chlorophylls, lies in the fact that metal complexes of the phthalocyanine system produce extremely intense and useful dyestuffs. Much research has therefore been devoted to physical and spectroscopic studies of these molecules (B-81MI30700). Phthalocyanines are extremely stable, are stable to light, and are insoluble in most solvents, so they are very useful dyestuffs. 

Virtually every conceivable chromophore has been used in the synthesis of reactive dyes, including monoazo and disazo species, metal complexes of azo dyes, formazan dyes, anthraquinones, triphenodioxazines, and phthalocyanines. The product lines offered by the major dye producers in most cases feature comparable chromophores, differing primarily in the nature of the reactive systems and the particular substitution patterns adopted. 

Additionally to the theoretical data and synthetic techniques for various metal complexes presented in Chaps. 2-A, we would like to pay special attention to three kinds of coordination compounds (complexes of phthalocyanines, quinones, and radioactive elements), whose syntheses, in our opinion, have been insufficiently generalized in monographs and textbooks on synthetic coordination chemistry. This choice is caused by the facts that phthalocyanines, as n-aromatic macrocyclic compounds, possess unusual thermal stability (nonstandard for organic and organometallic species) the quinone complexes have free-radical properties and coordination and organometallic compounds of radioactive elements are interesting at least for the reasons of necessity of special precautions in their syntheses and applications in the nuclear industry and nuclear medicine. So, this chapter is dedicated to the peculiarities of structure and properties and the main synthetic procedures for the complexes above. 

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