Palladium phthalocyanine preparation

Palladiumphthalocyanine (PcPd) can be synthesized from phthalimide, ammonium molyb-date(VI), urea and palladium(II) chloride in nitrobenzene.285 Peripherally substituted palladium phthalocyanine is prepared by the reaction of phthalonitrile286 or isoindolinediimine114,117 and palladium(II) acetate in 2-(dimethylamino)ethanol. Also a metal insertion into metal-free phthalocyanine in dimethylfonnamide starting from bis(triphenylphos-phane)palladium(II) chloride has been performed.141,287... 

Zeolite-encapsulated Fe-phthalocyanine catalysts were used in the palladium-catalyzed aerobic oxidation of hydroquinone to benzoquinone, in the oxidation of 1-octene to 2-octanone and in the oxidation of cyclohexene to 3-acetoxycyclohexene. The catalysts prepared by the ion-exchange and the ferrocene methods were similar in catalytic activity but the ion-exchange method was more reproducible. 

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... 

Palladium chlorophthalocyanine is formed when phthalonitrile is heated with palladous chloride. Like other nuclear halogen-substituted phthalocyanines, it will not sublime (11, 278). The unsubstituted derivative may be prepared by the dehydrogenation of tetracyclohexenotetrazaporphin with palladium black (113), or by the action of palladous chloride on lithium phthalocyanine in absolute alcohol (11). It is also possible to prepare the complex by dissolving palladium black in boiling phthalonitrile, a really remarkable reaction. 

The polymer support route is based on the fixation of a phthalonitrile (A) on a polymer, while a different phthalonitrile (B) is added forming a l 3-product, which can be isolated by removing it from the polymer. Unsymmetrically octalkoxy-substituted nickel palladium and platinum phthalocyanines have been prepared recently starting from differently disubstituted phthalonitriles [91]. 

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