Carboxylated copper phthalocyanines

There is an interesting technique which makes it possible to introduce carboxylic acid groups into a copper phthalocyanine structure by an economical route. Carrying out the phthalic anhydride/urea process in the presence of a small amount of trimellitic acid or another benzene polycarboxylic acid will afford a car-boxylated pigment. 

Standard cyan ink-jet dyes are C.I. Acid Blue 9, 42090 [3844-45-9] and C.I. DirectBlue 199, 74190 [12222-04-7], C.I. Acid Blue 9 is characterized by a superior brilliancy of shade and high color strength, but this triphenylmethane dye exhibits a low lightfastness. Copper phthalocyanine dye C.I. DirectBlue 199 is suited for many applications due to its superior lightfastness and thermal stability. To improve its moderate waterfastness on plain paper, novel cyan dyes have been launched based on the differential solubility approach by introducing carboxyl groups into the phthalocyanine moiety [3,12],... 

The water-soluble cyan dyes continue to be based on the copper phthalocyanine system. In this regard, C.I. Direct Blue 199 has proved effective, due to its good color strength and photostability. Carboxylated analogs of this... 

In an early investigation poly(4-vinylphthalic add anhydride) was converted with urea and CuQ to a polymer copper phthalocyanine . This polymer decomposes at 583 K. Because of the unsolubility, it was only possible to detect many unreacted carboxyl groups in the polymer. 

The first reports of metallomesogens capable of forming lyotropic columnar phases were by Gaspard, who described mesomorphism in peripherally carboxylated copper(II) phthalocyanines [203], although their phase behaviour was never properly... 

Carboxylic acids can be obtained from the oxidation of vicinal diols in the presence of cobalt complexes [320-322]. a-Ketols have been oxidized to a-diketones by Cu(II) in buffered aqueous pyridine and the reaction exhibits a rate-controlling enolization step [323]. The catalytic effect of Fe(III) and Fe(II) on the autoxidation of acetoin in aqueous HCIO4 showed that the formation of an iron(III) enolate was the slow step [324]. The oxidation of monosaccharides in the presence of catalysts such as copper phthalocyanine or cobalt glutamate in the presence of alkaline compounds gave oxidation products which were useful sequestering agents [325]. Thus cleavage to the acid salts occurred. 

Tetracarboxyphthalocyaninatocopper forms lyotropic phases in aqueous solution [162] as long as Li or Na are present as counterions [163]. From the investigated phthalocyanines nevertheless only the copper complex shows this lyotropic behavior. Likewise, the liquid crystalline characteristics disappear by substituting the carboxylate groups with sulfo groups [163]. 

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