Electrical conductivity phthalocyanine

The reddish metal was already known in prehistoric times. It occasionally occurs as a native metal, but mostly in conspicuous green ores, from which it is extracted relatively easily. It is convenient to work, but not very hard. Not very optimal as a tool ("Otzi the Iceman" had a copper axe with him). Only through the addition of tin is the more useful bronze obtained. Its zinc alloy is the versatile and widely used brass. Copper is one of the coinage metals. Water pipes are commonly made of copper. Its very good thermal and electrical conductivity is commonly exploited (cable ), as well as its durability (roofs, gutters), as the verdigris (basic copper carbonate) protects the metal. Cu phthalocyanines are the most beautiful blue pigments. Seems to be essential to all life as a trace element. In some molluscs, Cu replaces Fe in the heme complex. A 70-kg human contains 72 mg. 

Suga T, Isoda S, Kobayashi T (1999) Characterization and electrical conductivity of dithallium phthalocyanine (TI2PC). J Porphyrins Phthalocyanines 3 397-405... 

Table 3 shows the suitability of various types of carbon as substrate materials. The specific surface and the electrical conductivity play only a minor part. It is the nature of the oxygen-containing groups on the carbon surface that counts alkaline surface groups must be present if the phthalocyanine is to have a catalytic effect a>. 

Recent band structure calculations have confirmed that the increase in electrical conductivity of doped polymer phthalocyanines is the result of both the existence of partially filled bands and the decrease of the M—M distance.104 They also confirm that the conduction process for the doped polymers changes from metal-centred (M = Cr, Mn, Fe and Co), to ligand and metal (M = Ni) and to ligand-centred (Cu and Zn) with increasing electronegativity of the metal atom along the first transition series. 

Several polymers of Ni and Cu-phthalocyanine appeared to be more active than the corresponding monomers, and this was correlated with the thermal activation energy of the electrical conductivity. A complicating factor was that the H2 to C02 ratio was always smaller than one with the polymers, which means that part of the hydrogen was absorbed by the polymer, a phenomenon we have encountered earlier in the section on hydrogen activation. 

Polypyrrole complexed with cobalt-phthalocyanine [128] synthesized from the aqueous solution containing pyrrole and sodium salt of tetra- or mono-sulphonated cobalt-phthalocyanine, resulted in a highly electrochro-mic composite material. The electrical conductivity of the composite increased by two orders of magnitude more than that of the initial value on storage in ambient air for two months, whereas in the case of polypyrrole containing BF4, a 30-40% loss of electrical conductivity was observed. 

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