Copper phthalocyanine absorption spectra

Fig. 7. Photoresponse of copper phthalocyanine. Photocurrent units are arbitrary left scale refers to lower curve, which is the absorption spectrum. (From ref. 37)...

Fig. 26 a,b. Photoaction spectra of unsubstituted and substituted copper(II) phthalocyanines a) PcCu, b) MegPcCu (the dotted line represents the UV/VIS absorption spectrum)... 

Fig. 20.40 The electronic absorption spectrum of copper(II) phthalocyanine, [Cu(Pc)], (red trace) and an absorption spectrum of a different metal(II) phthalocyanine, [M(Pc)] (green trace). [Based on Figure 4 in P. Gregory in Comprehensive Coordination Chemistry II, 2004, Elsevier, Chapter 9.12, p. 549.].

Copper phthalocyanine blue pigments are soluble in concentrated sulfuric add. The solutions are quite stable at room temperature for several hours. The sample preparation for this analysis is quite simple. The pigment sample (3-5 mg) is weighed on a microbalance and then dissolved in concentrated sulfuric acid by stirring and/ or sonication. After complete dissolution the sample is diluted to a known volume and the Visible to Near IR spectrum is scanned from 400 to 900 run. Based on the absorbance and weight concentration of the sample and that of the reference pure standard at the wavelength of maximum absorption (Imax). the amount of pigment in the sample is determined. 

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