Platinum copper phthalocyanine

A similar behavior of the resistance of transparent nickel films was observed with the adsorption of triphenylmethane and naphthalene. In these cases the resistance decreased by 0.033 and 0.035% (18). As does the adsorption of benzene, the adsorption of triphenylmethane and of copper phthalocyanine lowers the electronic work function of a platinum surface (76). 

Fiq. 30. Change of photoelectric yield at X = 265.5 in/x by cooling of a platinum foil covered with copper-phthalocyanine molecules (a) cooling by liquid air (5) liquid air evaporated [according to (77a)],... 

Fig. 31. Fowler curves of platinum surface covered with copper-phthalocyanine molecules as in Fig. 30 at room temperature (I) and at low temperature (II) [according to (77a)].

Photoelectrochemical behavior of metal phthalocyanine solid films (p-type photoconductors) have been studied at both metal (93,94,95,96) and semiconductor (97,98) electrodes. Copper phthalocyanine vacuum-deposited on a Sn02 OTE (97) displayed photocurrents with signs depending on the thickness of film as well as the electrode potential. Besides anodic photocurrents due to normal dye sensitization phenomenon on an n-type semiconductor, enhanced cathodic photocurrents were observed with thicker films due to a bulk effect (p-type photoconductivity) of the dye layer. Meier et al. (9j>) studied the cathodic photocurrent behavior of various metal phthalocyanines on platinum electrodes where the dye layer acted as a typical p-type organic semiconductor. 

The insolubilities of phthalocyanines made their analysis difficult and it took some time before a satisfactory structure was elucidated. Initial work was undertaken by the Linstead group at Imperial College in the 1930s that culminated in a series of six back to back papers published in 1934 [14], It was also Linstead who named the compounds in recognition of their synthesis from phthalic anhydride and similarity to the blue cyanine dyes. Definitive characterization of the nickel, platinum and copper phthalocyanine complexes, together with the metal-free compound, was revealed in 1935 following the publication of their X-ray structures by Robertson [15] the copper and metal-free compounds are illustrated in Fig. 7.5. 

Honigman, B Lenne, H. U. and Schrddel, R. (1965). Relations between the structures of the modifications of the platinum and copper phthalocyanines and some chloride derivatives. Z. Kristallogr, 122, 185-205. [268]... 

Haak and Nolta (141, 14%) have observed rectifying phenomena when polycrystalline samples of metal-free or metal phthalocyanines are compressed between different metal electrodes. A small amount of a liquid polar impurity was found to be essential for rectification to occur. The rectification ratio (ratio of conductance in forward and reverse directions, the forward direction being movement of electrons from the least noble electrode to the sample) varies from 25 to 500. The latter value is obtained when copper phthalocyanine is sandwiched between either platinum and silver, or silver and aluminum, electrodes. Kleitman (188) has also demonstrated that metal-free phthalocyanine can act as a rectifier. 

One can also mention the case of composites-based conducting polymers electrodeposited and characterized on anodes of platinum- or carbon black- filled polypropylene from a stirred electrolyte with dispersed copper phthalocyanine. The electrolytic solution contained, besides the solvent (water or acetonitrile), the monomer (pyrrole or thiophene) and a supporting electrolyte. Patterned thin films were obtained from phthalocyanine derivatives, as reported in the case of (2,3,9,10,16,17,23,24-oktakis((2-benzyloxy)ethoxy)phthalocyaninato) copper . Such films were prepared by means of capillary flow of chloroform solutions into micrometer-dimension hydrophobic/hydrophilic channels initially created by a combination of microcontact printing of octadecylmercaptan (Cig-SH) layers on gold electrodes. These latter gave birth to a hydrophobic channel bottom while oxidative electropolymerization of w-aminophenol (at pH 4) led to hydrophilic channel walls. 

Zhong J, Fan Y, Wang H, Wang R, Fan L, Shen X, Shi Z (2013) Copper phthalocyanine functionalization of graphene nanosheets as support for platinum nanoparticles and their enhanced performance toward methanol oxidation. J Power Sour 242 208-215... 

Phthalocyanine was discovered by accident in 1907 when Braun and Tchemiac isolated a small amount of blue precipitate after heating o-cyanobenzamide in alcohol [41]. The chemical structure of phthalocyanine was established by Robertson and co-workers who reported the X-ray single crystal structures of nickel phthalocyanine, copper phthalocyanine and platinum phthalocyanine [42-45]. Phthalocyanines show intense... 

In an interesting study, phthalocyanine complexes containing four anthraquinone nuclei (5.34) were synthesised and evaluated as potential vat dyes and pigments [18]. Anthraquinone-1,2-dicarbonitrile or the corresponding dicarboxylic anhydride was reacted with a transition-metal salt, namely vanadium, chromium, iron, cobalt, nickel, copper, tin, platinum or lead (Scheme 5.6). Substituted analogues were also prepared from amino, chloro or nitro derivatives of anthraquinone-l,2-dicarboxylic anhydride. 

Robertson JM (1935) An X-ray study of the structure of the phthalocyanines. Part I. The metal-free, nickel, copper, and platinum compounds. J Chem Soc 615-621... 

Beevers, C. A., and Lipson, H. Crystal structure of copper sulphate pentahy-drate, CuS04-5H20. Proc. Roy. Soc. (London) A146, 570-582 (1934). Robertson, J. M. An X-ray study of the structure of the phthalocyanines. Part I. The metal-free, nickel, copper and platinum compounds. J. Chem. Soc. (London) 615-621 (1934). 

Some papers have appeared that deal with the use of electrodes whose surfaces are modified with materials suitable for the catalytic reduction of halogenated organic compounds. Kerr and coworkers [408] employed a platinum electrode coated with poly-/7-nitrostyrene for the catalytic reduction of l,2-dibromo-l,2-diphenylethane. Catalytic reduction of 1,2-dibromo-l,2-diphenylethane, 1,2-dibromophenylethane, and 1,2-dibromopropane has been achieved with an electrode coated with covalently immobilized cobalt(II) or copper(II) tetraphenylporphyrin [409]. Carbon electrodes modified with /nc50-tetra(/7-aminophenyl)porphyrinatoiron(III) can be used for the catalytic reduction of benzyl bromide, triphenylmethyl bromide, and hexachloroethane when the surface-bound porphyrin is in the Fe(T) state [410]. Metal phthalocyanine-containing films on pyrolytic graphite have been utilized for the catalytic reduction of P anj -1,2-dibromocyclohexane and trichloroacetic acid [411], and copper and nickel phthalocyanines adsorbed onto carbon promote the catalytic reduction of 1,2-dibromobutane, n-<7/ 5-l,2-dibromocyclohexane, and trichloroacetic acid in bicontinuous microemulsions [412]. When carbon electrodes coated with anodically polymerized films of nickel(Il) salen are cathodically polarized to generate nickel(I) sites, it is possible to carry out the catalytic reduction of iodoethane and 2-iodopropane [29] and the reductive intramolecular cyclizations of 1,3-dibromopropane and of 1,4-dibromo- and 1,4-diiodobutane [413]. A volume edited by Murray [414] contains a valuable set of review chapters by experts in the field of chemically modified electrodes. 

The compound phthalocyanine, C32H18N8, is of exceptional interest on chemical grounds in that in combination with the metals Be, Mn, Fe, Co, Ni, Cu and Pt it forms derivatives of composition C32H36N8M of quite extraordinary stability the copper compounds, for example, sublimes without decomposition at 580 °C. The structure analysis reveals that the parent metal-free substance and all these derivatives (except that of platinum) are isomorphous and have unit... 

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