Polyphthalocyanines

Butyroin has been prepared by reductive condensation of ethyl butyrate with sodium in xylene, or with sodium in the presence of chloro-trimethylsilane. and by reduction of 4,5-octanedlone with sodium l-benzyl-3-carbamoyl-l,4-dihydropyridine-4-sulfinate in the presence of magnesium chloride or with thiophenol in the presence of iron polyphthalocyanine as electron transfer agent.This acyloin has also been obtained by oxidation of (E)-4-octene with potassium permanganate and by reaction of... 

Lyubchenko LS, Stepanov SV, Lyubchenko ML, Sherle AI, Epstein VP, Dadali AA, Malinsky J (1992) Low-field microwave absorption in high-Fc superconductors based on olygo- and polyphthalocyanines. Phys Lett A162 69-78... 

Polymeric dyes, such as the polymeric phthalocyanines, become more conducting as the degree of polymerization increases. This is demonstrated in Fig. 5 for polymeric Fe- and Co-polyphthalocyanines 65>. 

Fig. 5. Relationship between thermal activation energy and dark conductivity AEn=f (log od).------ Fe-polyphthalocyanine .Co-polyphthalocyanine...

However, Fig. 5 also indicates that where there is disturbance of the delocalization of 7i electrons the AEn values and the corresponding an values [resulting from Eq. (50)] tend toward a limit. Thus, as in other organic semiconductors, we have to distinguish between rubiconjugated compounds (characterized by a disturbed delocalization as in Fe-polyphthalocyanines) and ekaconjugated compounds (characterized by an undisturbed delocalization of electrons as in Cu-polyphthalocyanines). 

Example the oxidation of acetaldehyde ethylene acetal to ethylene glycol monoacetate with Fe—M-polyphthalocyanines (M V, Cr, Cu, etc.) as catalysts 110>. 

Table 10. Relation between catalytic activity of H2O2 decomposition (given in time 50 [min] necessary for a decomposition of 50% H202) and dark conductivity of Co-polyphthalocyanines (from Ref. 5))...

Similar results have been obtained with Cu-phthalocyanine samples ail> and Fe-polyphthalocyanines 65>. 

Moreover, the conductivity, and hence the catalytic decomposition of hydrogen peroxide, has been observed to influence the stability of the oxygen electrode. The stability of phthalocyanine catalysts is a decisive factor for the practical applicability of organic catalysts in fuel cells operating in an acid medium. This is therefore a very important observation. The observed disturbance of the delocalization of the n electrons (rubiconjugation) in Fe-polyphthalocyanines, in addition to the correlation between conductivity on the one hand, and electrocatalysis and catalytic decomposition of hydrogen peroxide on the other, leads to a special model of the electroreduction of oxygen on phthalocyanines. The model... 

Table 11. Relation between electrocatalytic activity (given in the potential 20 measured at a current density of 20 mA/cm2) and conductivity in Fe-polyphthalocyanine samples (from Ref. e5>)...

Fe-polyphthalocyanine [sample No] Electrocatalytic activity y>20 [mV] Dark conductivity ctd [ohm-tcm-1]... 

Yet it will be necessary to look for systems having higher conductivities, since a Peltier refrigerator, for example, would become competitive in its power consumption only above an effectivity of Gx = 6 x 10-3 deg-1. It is probable that this aim will be reached. Table 12 shows a Cu-polyphthalocyanine sample with a remarkably favorable Gx value of about 5 x 10 4 deg-1. 

Silica-supported cyclized polyacrylonitrile (PAN) metal complexes, claimed to be better oxidation catalysts than the polyphthalocyanine-metal complexes, have been obtained shown below as [11] ... 

Figure 5.15. A schematic view of part of a bridge-stacked polyphthalocyanine.

Inoue, H., Kida, Y., Imoto, E. The Catalytic Action of Binary Metal-Polyphthalocyanine Complexes on the Oxidation of Acetaldehyde Ethylene Acetal. Bull. Chem. Soc. Japan 38, 2214(1965). 

Organic Catalysts. III. The Catalytic Action of Copper-Iron Polyphthalocyanine... 

The potent reductant Smh readily reduces a-alkylthio, a-sulfinyl and a-sulfonyl ketones at -78 °C A mixture of iron(II) polyphthalocyanine and thiophenol has been used to reduce a-halo, a-alkylthio, and a,a-bis(alkylthio) ketones. The iron compound apparently reacts as an electron transfer mediator the actual source of electrons is the thiophenol, which is converted to diphenyl disulfide in the course of the reaction. 

Figure 1. Similarity of the electronic spectra of phthalocyanine, with cumylphe-noxyphthalocyanine (VII) and the polyphthalocyanine (II).

More recently, the kinetics and the effect of solvents on the oxidation catalysed by metal polyphthalocyanines and porphyrins (M—P) has been studied [71]. It was suggested that the initiation process is... 

Other systems, such as polydiacetylenes, and also polyphthalocyanines, have been examined recent investigations on thiophene oligomers and polymers, in forms of thin films, are in progress. 

Copper-iron-polyphthalocyanine [251,252] showed a specific catalysis for the oxidations of saturated aldehydes and substituted benzaldehydes with oxygen. The catalytic reaction was solvent dependent so that tetrahydrofuran, ethanol, acetonitrile, ethyl acetate and anisole inhibited benzaldehyde oxidation while oxidation occurred readily in benzene or acetone. Benzaldehyde was catalytically oxidized with copper-iron-polyphthalocyanine and oxygen to give a quantitative yield of a mixture of perbenzoic (61%) and benzoic (39%) acids. Reaction was carried out at 30 °C and atmospheric pressure of oxygen and exhibited no induction period. By contrast p-methyl and p-chlorobenzaldehyde had induction periods of 8 and 15 min respectively while no oxidation of p-substituted benzaldehydes was observed when the para-substituent was NO2, OH, OCH3, or N(CH3)2. 

Inoue, Kida and Imoto [252] found that the oxidation of unsaturated aldehydes such as cinnamaldehyde and acrolein proceeded much more slowly than did oxidation of the saturated substrates in the presence of copper-iron-polyphthalocyanine. As in the case of the saturated acids the products were a mixture of the peracid and the corresponding carboxylic acid. Other groups have recently investigated the oxidation of unsaturated aldehydes in the presence of metal complexes [253-260]. Methacrylic acid and acetic acid were formed in the copper naphthenate catalyzed oxidation of methacrolein [255]. The oxidation of acrolein to acrylic acid was catalyzed by Co, Ni, Mn and Cu acetates [256]. It was found that at concentrations of acrolein in... 

Polyphthalocyanines Silver, Aluminum, Zinc, Tungsten, Cadmium,... 

---