Copper complexes phthalocyanines

Figure 10.12 2,17-Bis-sulfonato-5,10,15-tri(pentafluorophenyl)corrole manganese complex 14 [59,60], tetrakis(sulfonato) phthalocyanin copper complex 15 [61], and meso-tetrakis (p-carboxyphenyl)-porphyrln manganese complex 16 [62].

Reetz and Jiao demonstrated the use of phthalocyanine-copper complex (267) in combination with a number of serum albumins as protein hosts in enantioselective Diels-Alder reactions of cyclopentadiene with azachalcones (Scheme 17.60) [86]. The combination of achiral Lewis acid (267) and bovine serum albumin as chiral host was determined to be optimal, giving the desired cycloadducts in good to excellent selectivities. Human, porcine, and sheep serum albumins also gave significant enantioselectivity, while rabbit and chicken-egg serum albumins resulted in nearly racemic cycloadduct. 

An appropriate ion-specific electrode was found to provide a convenient, precise and relatively inexpensive method for potentiometry of copper(II) ion in copper-complex azo or formazan dyes. Copper(II) ion in copper phthalocyanine dyes can be quantified after anion exchange. Twelve commercial premetallised dyes evaluated using this technique contained copper(II) ion concentrations in the range 0.007 to 0.2%. Thus many copper-complex direct or reactive dyes are likely to contribute low but possibly significant amounts of ionic copper to textile dyeing effluents [52]. 

At present, synthetic routes to more than 40 metal complexes other than the copper complex are known. Apart from a cobalt phthalocyanine pigment (P.B.75) which was introduced to the market just recently, none of the resulting products, however, has stimulated commercial interest as a pigment. Nickel complexes, however, are found in reactive dyes, while cobalt complexes of this basic structure are employed as developing dyes. 

As early as 1907, A.V. Braun and J. Tscherniak first obtained phthalocyanine from phthalimide and acetic anhydride [5]. The prepared blue substance, however, was not investigated further. In 1927, de Diesbach and von der Weid, in an attempt to synthesize phthalonitrile from o-dibromobenzene and copper cyanide in pyridine at 200°C, obtained a blue copper complex. The substance was found to be exceptionally fast to acid, alkali, and high temperature [6], Approximately one year later, in trying to manufacture phthalimide from phthalic anhydride and ammo-... 

In 1929, Linsted obtained samples of this complex from ICI chemists (Scottish Dyes Ltd was now owned by ICI). ICI had developed two routes leading to the phthalocyanine iron complex. One method started from phthalic anhydride, iron, and ammonia, while the second pathway proceeded from phthalimide, iron sulfide, and ammonia. In 1933/34, elucidation of the phthalocyanine structure was credited to Linstead. The corresponding copper and nickel phthalocyanines had been prepared in the meantime. ICI introduced the first Copper Phthalocyanine Blue to the market as early as 1935, and the Ludwigshafen subsidiary of the IG Farben-industrie followed suit with a corresponding product. 

The similarly blue and equally polymorphous metal-free phthalocyanine existing in five different crystal modifications (a, (3, y, k, t) is chemically somewhat less stable than its copper complex [26] it decomposes slowly in a sulfuric acid solution. On the other hand, it can be chlorinated to afford metal-free Phthalocyanine Green. 

The phthalocyanines, naphthalocyanines, and certain of their metal derivatives (Figure 6.17) are infrared fluorophores. 61"64 As a class, they are exceptionally stable compounds, with copper (Cu) phthalocyanine (not a fluorophore) remaining intact above 300 °C in air. First used for textile dyeing in the last century and still widely used, there is a rich chemistry of phthalocyanines. Most derivatives can be made by prolonged heating of a phthalimide or phthalic acid derivative with a metal in powder or salt form at elevated temperature. Several derivatives absorb in the near-IR, and either fluoresce or phosphoresce. The electronic transitions of phthalocyanines are complex and have been extensively studied, at least in part because the symmetry of the molecule makes theoretical calculations of its spectroscopic behavior more tractable. Unsubstituted phthalocyanines and naphthalocyanines are, as a class, very insoluble in solvents other than, for instance, nitrobenzene. Sulfonated phthalocyanines are water soluble and exhibit spectra comparable to the parent derivative. Photolumines-cent phthalocyanines (Pcs) include SiPc, ZnPc, and PC itself. These compounds have been little used for practical infrared fluorometry to date however, Diatron Corpora-... 

Oxygenic photosynthetic organisms, [2Fe-2S] ferredoxins, 38 224-233 Oxygenyl ion, preparation of, 9 229 Oxyhalides, of berkelium, 28 49, 51-53 Oxyhalogeno cations, 9 276-279 Oxyhemerythrin, 40 373-374, 45 84 XAS, 36 325 Oxyhemocyanin, 40 363 m-peroxo dinuclear copper complexes as models for, 39 41-52 physicochemical properties, 39 47-48 Oxyhemocyanins, XAS, 36 326-327 Oxyhemoglobin, 21 135 Oxyiodonium cations, 9 277 Oxymanganese phthalocyanine, strucmre of, 7 31-35... 

Copper phthalocyanine (1) was developed in the 1930s and is the most commonly used blue organic pigment in the coatings, paint, and printing inks industry. Phthalocyanine forms complexes with numerous metals. Various complexes with 66 chemical elements are known. Phthalocyanines are structurally related to naturally occurring dyes such as hemoglobin and chlorophyll A. 

Despite the expenditure of a tremendous amount of effort throughout the world, the two original methods employed in the manufacture of copper phthalocyanine are still used. In the first, a mixture of phthalic anhydride, urea and copper(I) chloride is heated in a high-boiling solvent such as nitrobenzene or trichlorobenzene in the presence of a catalytic amount of ammonium molybdate. The crude copper phthalocyanine is filtered off and the solvent recovered by distillation. The urea acts as a source of nitrogen and the first step in the overall reaction (equation 18) is conversion of phthalic anhydride to phthalimide (219) by ammonia liberated by the urea. More ammonia then converts the phthalimide to l-keto-3-iminoisoindoline (220) and finally to l-amino-3-iminoisoin-dolenine (221). All three intermediates have been isolated and identified. In the presence of copper chloride the l-amino-3-iminoisoindolenine undergoes conversion to the copper complex of phthalocyanine. 

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... 

A large class of coordination compounds, metal chelates, is represented in relation to microwave treatment by a relatively small number of reported data, mainly p-diketonates. Thus, volatile copper) II) acetylacetonate was used for the preparation of copper thin films in Ar — H2 atmosphere at ambient temperature by microwave plasma-enhanced chemical vapor deposition (CVD) [735a]. The formed pure copper films with a resistance of 2 3 pS2 cm were deposited on Si substrates. It is noted that oxygen atoms were never detected in the deposited material since Cu — O intramolecular bonds are totally broken by microwave plasma-assisted decomposition of the copper complex. Another acetylacetonate, Zr(acac)4, was prepared from its hydrate Zr(acac)4 10H2O by microwave dehydration of the latter [726]. It is shown [704] that microwave treatment is an effective dehydration technique for various compounds and materials. Use of microwave irradiation in the synthesis of some transition metal phthalocyanines is reported in Sec. 5.1.1. Their relatives - porphyrins - were also obtained in this way [735b]. 

Most reported phthalocyanine derivatives (sulfo-, nitro-, amino-, triphenylmethyl-, polymeric, etc.) are copper complexes, although at present the synthetic chemistry of other d- and /-metal Pc derivatives is being rapidly developed (Examples 30-36) [5,6,116-118]. Some of them (in particular, copper phthalocyanine sulfonic acids) are of industrial interest because of their usefulness as dyes. Phthalocyanine sulfonic acids themselves are prepared both by urea synthesis from sulfonated phthalic anhydride and by the sulfonation of the phthalocyanine [6], Some substituted metal phthalocyanines can be obtained by chemical or electrochemical reduction [118e]. Among a number of reported peculiarities of substituted phthalocyanines, the existence of three electronic isomers for magnesium derivative PcMn was recently confirmed [118f]. 

The last category was concerned with miscellaneous subjects, while citing some chirogenic porphyrin-based systems. Representative reviews include chiral lanthanide complexes by Aspinall [41], coordination chemistry of tin porphyrins by Arnold and Blok [42], photoprocesses of copper complexes that bind to DNA by McMillin and McNett [43], nonplanar porphyrins and their significance in proteins by Shelnutt et al. [44], cytochrome P450 biomimetic systems by Feiters, Rowan, and Nolte [45] and phthalocyanines by Kobayashi [46,47]. 

Fig. 7.5 Phthalocyanine crystal structures a copper complex [12] (left) and the metal free macrocycle [13] (right)...

The use of metal ions as templates for macrocycle synthesis has an obvious relevance to the understanding of how biological molecules are formed in vivo. The early synthesis of phthalocyanins from phthalonitrile in the presence of metal salts (89) has been followed by the use of Cu(II) salts as templates in the synthesis of copper complexes of etioporphyrin-I (32), tetraethoxycarbonylporphyrin (26), etioporphyrin-II (78), and coproporphyrin-II (81). Metal ions have also been used as templates in the synthesis of corrins, e.g., nickel and cobalt ions in the synthesis of tetradehydrocorrin complexes (64) and nickel ions to hold the two halves of a corrin ring system while cycliza-tion was effected (51), and other biological molecules (67, 76, 77). 

---