Silver complexes phthalocyanines

Copper, and occasionally silver, have been used as catalysts for hydroformylation of a-olefins. Phosphite complexes of copper(I) chloride have been claimed as catalysts (126). Phthalocyanine complexes of Group IB metals have been stated to show a low degree of catalytic activity (127). One of the more interesting examples of copper catalysis was disclosed by McClure (128). Copper powder, with a controlled amount of water (0.2-4.0 moles H20/mole Cu), gave a slow conversion of pro-... 

A black-and-white system based on the silver dye-bleach process contains the single azoxy copper-complexed dye (36).10P During bleaching, low pH solutions are used and the dye is partially demetallized. This necessitates an after-bath treatment with a copper-containing solution. Dyes other than those containing the azo group can also be bleached, and derivatives of sulfonated copper phthalocyanine have been used to form cyan images.101... 

Palladium, platinum, and silver pthalocyaninates - 5,6-Di-substituted isoindoles were condensed in the presence of Pd(acac)2 or PtCl2 to obtain soluble octa-alkoxy-substituted phthalocyaninato palladium(II) and platinum(II) complexes [121]. Tetrakis-(neopentyloxy) phthalocyaninatosilver(II) was obtained in high yield from AgN03 and the respective metal free phthalocyanine in DMF at 75 °C [122],... 

Phthalocyanine is a divalent ligand with a geometry appropriate for forming a four-coordinated square-planar complex and was thought ideal for generating an Au(II) species. The action of AuBr on molten 1,3-diiminoisoindoline in the absence of solvent indeed yields a neutral gold phthalocyanine (63). The EPR spectra of the complex in 1-chloronaphthalene at 77 K clearly showed the presence of Au(II), a d9 ion. The g value is 2.065, comparable to 2.042 for copper and 2.093 for silver phthalocyanine (64, 80). 

Custom modifications have previously been developed whereby a non-fluorescent chromophore can be attached to the DNA sequence to provide a strong SE(R)RS signature which is indicative of the DNA sequence present. This has been done previously using DABCYL, phthalocyanines and black hole quenchers (BHQs) as well as specifically designed simple azo dyes which contain moieties to aid in their binding ability to metal surfaces such as the benzotriazole motif which has been shown to be very effective at complexing onto silver nanoparticles [12, 13, 40, 41]. 

Equations (II) to (IX) illustrate basic methods of preparation, but many variations are used, particularly in industry, to obtain an economic yield. Phthalic acid, phthalamide, phthalimide, and phthalic anhydride, together with urea, are often used instead of phthalonitrile, and catalysts such as ammonium molybdate or zirconium tetrachloride may be employed (249, 251, 269). The reaction between phthalonitrile and metals (finely divided or acid-etched) is usually very vigorous at 250°-300°C, sufficient heat being generated to maintain the reaction temperature. This is an illustration of the ease with which the phthalocyanine skeleton is formed. Even more surprising are the observations that palladium black (118) and gold (189) will dissolve in molten phthalonitrile. Reaction (III) between phthalonitrile and a finely divided metal, metal hydride, oxide, or chloride is perhaps the most generally employed. For the unstable phthalocyanine complexes such as that of silver (11), the double decomposition reaction... 

Dichlorosilicon phthalocyanine (XIX) is prepared from silicon tetrachloride and phthalonitrile in quinoline at 200°C 168,170). The blue-green crystals, which sublime readily at 430°C in vacuo, hydrolyze forming dihydroxysilicon phthalocyanine (XX) when refluxed with equal volumes of pyridine and aqueous ammonia (200). The corresponding difluorosilicon phthalocyanine is resistant to hydrolysis. Conversion of the chloride to the corresponding dicyanate, dithiocyanate, and diselenocyanate occurs upon reaction with the appropriate silver pseudohalide (178). The complexes are believed to involve nitrogen to silicon bonding in the case of the thiocyanate and selenocyanate. 

Arsenic trichloride reacts with dilithium phthalocyanine in dimethyl-formamide to yield chloroarsenic phthalocyanine 808), which does not react with silver ions in pyridine. Its absorption spectrum has been recorded (Section V,B), but little else is known of the complex. 

Table VI lists all the published electron-spin resonance data pertaining to paramagnetic metal phthalocyanines. In addition to the g values, the most commonly recorded datum is the a2 value a = a2 = 1 refers to purely ionic bonding (LXXVII) and values of a2 less than 1 imply some delocalization of the dxi-yi electron onto the phthalocyanine ligand. Thus the value of a2 = 0.54 for silver phthalocyanine may be interpreted to mean that the dtf-yi electron spends 46% of its time on the phthalocyanine ligand. The comparatively low values of a2 reported for copper and silver phthalocyanine 131, 139, 145, 237, 260, 298, 347) suggest a high degree of covalency in these complexes.

By far the most detailed thermodynamic studies have been made by Berezin, who has looked at the equilibria existing in concentrated sulfuric acid. Linstead s group were the first to observe that some of the metal phthalocyanines were demetallated in concentrated sulfuric acid, whereas others appeared indefinitely stable (10). It was shown that all phthalocyanines which resisted attack were of metals whose radii were of the right size to fit nicely into the space available at the center of the ligand. Berezin has since put these observations on a more quantitative basis (19, 21, 26). Labile complexes (i.e., those which are demetallated instantly or fairly rapidly in concentrated sulfuric acid) include those of the alkali metals, alkaline earth metals, Be, Mg, Cd, Hg, Sb(III), Pb, Sn(II), Mn(II), and Fe(III). Stable complexes (demetallated very slowly in acid) include those of Zn, Al, Cl2Sn(IV), OV(IV), Co(II), Rh(II), Os(IV), Ni(II), Pd(II), Pt(II), and Cu(II). The actual rates of decomposition vary widely thus, while calcium and magnesium phthalocyanines are demetallated very rapidly, silver and lead phthalocyanines react fairly slowly (19). The rates of decomposition in 1 M sulfuric acid increase in the sequence (19) Fe(III)... 

A novel compacted electrode technique has been described for producing a coating of the insoluble pigment a-copper phthalocyanine on a silver surface [34]. Such films of phthalocyanines and their metal complexes on metal surfaces are useful in a wide range of solid-state devices. Again, a combination of RR and SER spectra has been used to characterize these electrodes and the changes which occur in them when the electrode potential is varied. 

Silver(n) complexes, 839-850 amino adds, 846 aqua,844,850 biguanides, 849 2,2 -bipyridyl, 843 carboxylates, 844 cinchomeronic acid, 842 dipicolinic acid, 842 dithiocarbamates, 845 isodnchomcronic add, 842 isonicotinates, 840 lutidinic acid, 842 N-heterocyclic ligands, 839 nicotinates, 840 1,10-phenanthroline, 843 phthalocyanines, 848 picolinates, 840... 

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