Chromium complexes phthalocyanines

Chromium(II) phthalocyanine (PcCr) is prepared from phthalonitrile and hexacarbonylchro-mium(O) in 1-chlornaphthalene.234 PcCr(OAc) is prepared from phthalonitrile and chro-mium(III) acetate without solvent235 or in nitrobenzene starting from chromium(II) acetate236 under reflux. Chromium(lll) phthalocyanine also forms /t-oxo dimeric complexes,237 which are more common with iron phthalocyanines. 

Since complexes of 2,2 -bipyridyl and 1,10-phenanthroline with chromium in oxidation states I and 0 can be obtained by reduction (Scheme 64) of the chromium(n) complexes, these oxidation states will be considered together. Oxidation, as shown in Schemes 65 and 68 of Section 35.4.2.5, gives chromium(III) complexes, which are often best prepared in this way. Earlier work has been extensively reviewed, and few complexes of 2,2 6, 2"-terpyridyl are known.32 A chromium(I) phthalocyanine derivative is mentioned in Section 35.4.9.3. 

Relatively few chromium complexes with phthalocyanine ligands have been reported and, ir view of the chemical relationship between the few known compounds, all of them, irrespectivt of the metal oxidation state, are dealt with in this section. In the following discussion Pi represents the dianionic phthalocyanine ligand. 

Examples of dye developers derived from heterocycles are the pyrazole (73), the chromium complex (74) and the phthalocyanine (75) (74MI11401). The pyrazole (76) is a... 

In an interesting study, phthalocyanine complexes containing four anthraquinone nuclei (5.34) were synthesised and evaluated as potential vat dyes and pigments [18]. Anthraquinone-1,2-dicarbonitrile or the corresponding dicarboxylic anhydride was reacted with a transition-metal salt, namely vanadium, chromium, iron, cobalt, nickel, copper, tin, platinum or lead (Scheme 5.6). Substituted analogues were also prepared from amino, chloro or nitro derivatives of anthraquinone-l,2-dicarboxylic anhydride. 

Direct Dyes. These water-soluble anionic dyes, when dyed from aqueous solution in the presence of electrolytes, are substantive to, i.e., have high affinity for, cellu-losic fibers. Their principal use is the dyeing of cotton and regenerated cellulose, paper, leather, and, to a lesser extent, nylon. Most of the dyes in this class are polyazo compounds, along with some stilbenes, phthalocyanines, and oxazines. Aftertreatments, frequently applied to the dyed material to improve washfastness properties, include chelation with salts of metals (usually copper or chromium), and treatment with formaldehyde or a cationic dye-complexing resin. 

Solvent dyes for solvent based ink-jet inks and hot melt ink-jet systems are selected 1 2 chromium or cobalt complex azo (C.I. Solvent Yellow 83 1 [61116-27-6], C.I. Solvent Red 91 [61901-92-6]), anthraquinone (C.I. Solvent Blue 45 [37229-23-5]), or phthalocyanine (C.I. Solvent Blue 44 [61725-69-7]) dyes. 

The tetrasulfo-Pc complexes of a number of metals are made by the urea melt process by heating the powdered metal, or its acetate, with triammonium-4-sulfophthalate, urea, boric acid, and ammonium molybdate. The metals or metal compounds used are those of chromium (III), manganese(II), iron(II), iron(III), cobalt(II), and zinc(II). Selected synthetic examples of sulfo- and other derivatives of metal phthalocyanines are presented below. 

Recent reviews of the phthalocyanines by Lever (57) and by Moser and Thomas 66) are available. Complexes of phthalocyanine with all of the first row transition elements, excepting scandium, have been prepared. However, titanium and vanadium phthalocyanines are known only as the oxy- or chloro-compounds and are not then strictly square planar. That phthalocyanine has considerable ability to promote the square planar configuration is further demonstrated by the existence of the chromium (III) and manganese(II) complexes (57). 

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