Phthalocyanine green, structure

The phthalocyanines can be laid down as vividly coloured thin films by sublimation at high temperatures, e.g. at 400-600 °C under vacuum. The thin blue films of the bis-phthalocyanines are polyelecfiochromic, undergoing electrochemical oxidation to give first green and then yellow-red or red colours (anodic products) and blue-purple colours on reduction (cathodic products). The various structures of these coloured products are shown in Table 1.12. 

The term phthalocyanine was first used by R. P. Linstead in 1933 [1] to describe a class of organic dyes, whose colors range from reddish blue to yellowish green. The name phthalocyanine originates from the Greek terms naphtha for mineral oil and cyanine for dark blue. In 1930-1940, Linstead et al. elucidated the structure of phthalocyanine (H2Pc) and its metal complexes [1-11]. The basic structure is represented by phthalocyanine (1) itself ... 

The principal chromophores in pseudo sulfur dyes are copper and cobalt phthalocyanines, e.g., in C.I. Sulphur Green 25 (16), and the perylene tetracar-boxylic diimide structure in C.I. Sulphur Red 14 [81209-07-6] and C.I. Solubilised Sulfur Red 11 [61969-41-3] (17). In contrast to the sulfur dye made from Cu phthalocyanine, the cobalt derivative can be applied with dithionite. 

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