Polycarbonate soluble dyes

The novel water-soluble dye 64 shows sufficient stability for potential application in molecular-based beacons for cancer detection using optical imaging <2005BCC735>. An optochemical ozone sensor with a quantitation limit of 0.03 ppm and accuracy exceeding 8% has been obtained by immobilization of the novel soluble indigo derivative 65 in permeable transparent polymeric films of polydimethylsiloxane-polycarbonate <2005MI1628>. 

Phthalocyanine-based dyes are especially useful for CD-R, as the chromophore absorption band falls in the desirable spectral range, and they are noted for excellent photostability. Unlike cyanine dyes, phthalocyanines tend to have very poor solubility, particularly in solvents such as alcohols and aliphatic hydrocarbons (which do not attack polycarbonate and are therefore used for spin coating). Therefore, the main barrier to the wider use of these dyes is the relatively high cost of synthesizing soluble derivatives. Suitable modifications to the Pc core which have been developed, notably by Mitsui Toatsu, are shown in Scheme 7. The bulky R groups reduce undesirable molecular association (which in turn lower the extinction coefficient and hence reflectivity), whereas partial bromination allows fine-tuning of the film absorbance and reflectivity. The metal atom influences the position of the absorption band, the photostability, and the efficiency of the radiationless transition from the excited state.199 This material is marketed by Ciba as Supergreen.204... 

Naphthalocyanine Derivatives. These dyes, which contain a naphthalocyanine skeleton as chromophore, show high absorption in the area around 830 nm, possess low melting points, and small heat conductivity. A disadvantage of the unsubstituated naphthalocyanine is its low solubility in organic solvents which do not attack the polymeric substrate material (generally polycarbonate) substituents improve solubility (see PHTHALOCYANINE compounds). 

We reported a new method which allows for the rapid parallel solubility measurements for libraries of materials in SCFs [75]. The technique was used to evaluate the solubility of a mixed hbrary of 100 synthetic polymers including polyesters, polycarbonates, and vinyl polymers. It was found that poly(vinyl acetate) (PVAc) showed the highest solubility in CO2 the anomalously high solubility of PVAc has been shown previously [72]. This method is at least 50 times faster than other techniques in terms of the rate of useful information that is obtained and has broad utility in the discovery of novel SCF-soluble ligands, catalysts, biomolecules, dyes, or pharmaceuticals for a wide range of materials applications. 

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