Ali Rıza Özkaya

Electrochemical properties of octakis(hydroxyethylthio)-substituted phthalocyanines

Cyclic voltammetry of octakis(hydroxyethylthio)-substituted phthalocyanines with 2H (H2OHETPc), Zn(II) (ZnIIOHETPc(−2)) and Co(II) (CoII(OHETPc(−2)) in the phthalocyanine core has been investigated in dimethylsulfoxide (DMSO), and some of the results were evaluated together with their absorption spectra in the visible range. The redox processes due to both aggregated and non-aggregated species were observed on the voltammograms of phthalocyanines with Zn(II). The effect of chloride ion on the cyclic voltammetry of CoIIOHETPc(−2) has been investigated in the DMSO/ClO4− couple. The comparison of cyclic voltammetry for CoIIOHETPc in the absence and presence of chloride ion showed that chloride ion does not bind to either Co(II) or Co(I) but does bind very strongly to Co(III). The detailed electrochemistry of CoIIOHETPc(−2) was investigated in terms of the Co(I)/Co(II) and Co(II)/Co(III) redox couples, and various equilibria related to the species coordinated to Co(II) and Co(III) in the phthalocyanine core.

Electrochemical and spectral properties of octakis(hexylthio)-substituted phthalocyanines

Abstract The redox properties of octakis(hexylthio)-substituted phthalocyanines with 2H, ZnII and CuII in the phthalocyanine core have been investigated by cyclic voltammetry in dichloromethane and the energies of photo-excitation and oxido-reduction processes have been compared. Two successive one-electron reduction and one-electron oxidation processes were observed for the complexes used in this work. The displacement of two protons in the inner core with metal ion was found to shift the first reduction potential of phthalocyanine ring to more negative values as a result of the π-back donation of the filld dπ of metal ion into the empty pc-π ∗ orbitals. The evaluation of cyclic voltammetry data together with the absorption spectra showed that photoexciatation arises from the orbitals below the HOMO for all the complexes used in this work.

Synthesis and Electrochemistry of Soluble Phthalocyanine Complexes Containing Four Peripheral Dihexyl and Dihexylhexylmalonate Residues

Summary. Tetrasubstituted phthalocyanines bearing four dihexylmalonate or dihexylhexylmalonate residues on the periphery (M[Pc(CH(COOC6H13)2)4] or M[Pc(C(COOC6H13)2 C6H13)4]; M = Pd(II), Cu(II), Co(II)) were synthesized from the anhydrous metal salts and the corresponding phthalonitriles. The complexes were only slightly soluble in polar solvents such as methanol and ethanol, but more soluble in less polar solvents such as benzene, toluene, and even hexane. The spectroscopic properties of the complexes were affected strongly by the electron withdrawing malonate units. Cyclic voltammetry on a platinum electrode in dichloromethane showed ligand-based one-electron transfers for Cu and Pd compounds, whereas the Co complex displayed metal-based or/and ligand-based one-electron transfers depending on the supporting electrolyte anion. The structures were confirmed by elemental analysis, 1H NMR, 13C NMR, IR, mass (EI and FAB), and UV/Vis spectroscopy.

Synthesis, characterization, and electrical, electrochemical and gas sensing properties of a novel ball-type four t-butylcalix[4]arene bridged binuclear zinc(II) phthalocyanine.

1,3 dimethoxy-4-t-butylcalix[4]arene has been used to synthesize a novel ball-type dimeric zinc(II) phthalocyanine, [Zn2Pc2(tbca)4] that exhibits mixed-valence behaviour and non-Arrhenius type dependence of conductivity.

Electrochemical and Adsorption Properties of Novel Phthalocyanines with Four 16-Membered Diazadithia Macrocycles

Cyclic voltammetric measurements of Cu(II) and Ni(II) phthalocyanines with four 16-membered diazadithia macrocycles (1 and 2) and pentanuclear Ni(II) phthalocyanine bearing four Cu(II) ions in diazadithia macrocycles at the peripheral positions (3) have been carried out on platinum in DMSO and in aqueous medium 3 showed strong adsorption properties in DMSO and especially in aqueous medium, possibly as a result of the interaction between the copper ions in the four macrocycles and the platinum working electrode. Interestingly, the oxidation peak of 3 was split into two waves in aqueous medium. This behaviour is discussed in terms of disaggregation of the mixed valence species produced by the oxidation of aggregated species. A mechanism for both the oxidation of the complex and the splitting of the oxidation peak into two waves is suggested.

Synthesis, characterization, and electrical and electrochemical properties of sandwich dilutetium tetraphthalocyanine

Lu2Pc2 and lithium hexylthio-phthalocyanine have been used to synthesize [Lu2(Pc)4] which exhibits variable range hopping conductivity as inorganic semiconductors and also observed electrochromic effect from cyclic voltammetric (CV) measurement.

ELECTROCHEMICAL STUDIES OF TETRACROWN-ETHER SUBSTITUTED PHTHALOCYANINES IN SOLUTION

Abstract Cyclic voltammetry of soluble metal-free and copper phthalocyanines with crown ethers attached to the periphery through oxymethyl bridges show two one-electron reduction processes on sweeping to negative potentials. The addition of sodium or potassium ions to the solution results in a decrease in diffusion coefficients, which is a consequence of intermolecular complex formation in the presence of these two cations.

A novel (E,E)-dioxime and its mono-, di- and trinuclear complexes bearing tetradentate octyl sulfanyl phenylamino substituents. Synthesis, characterization and electrochemical properties of its transition metal complexes

A new vic-dioxime, 13,14-bis-(hydroxyimino)-9,12,15,18-diazadithiaoctacosane, has been synthesized from 2-octylsulfanylaminobenzene and (E,E′)-dichloroglyoxime. Mononuclear transition metal complexes of NiII, CuII, CoII and FeII have been prepared and were found to have a metal–ligand ratio of 1:2. The synthesis of di- and trinuclear complexes was achieved with UIVO2 and CuII depending on the stoichiometry of the reactants. The complexes were characterized by elemental analysis, 1H-n.m.r., u.v.–vis, i.r., f.a.b.-m.s. and by cyclic voltammetry.

Coumarin-substituted manganese phthalocyanines: synthesis, characterization, photovoltaic behaviour, spectral and electrochemical properties.

The synthesis and spectroscopic characterization of novel manganese(III) phthalocyanines bearing 7-oxy-4-(4-methoxyphenyl)-8-methylcoumarin or/and chloro groups have been achieved. The effect of alpha and beta substitution on the ligand- and metal-based reduction processes of the manganese phthalocyanine complexes and their interaction with dioxygen were investigated. The more effective interaction of the central metal of the beta coumarin substituted complex with dioxygen than that of its alpha substituted analogue was attributed to the hindrance of the interaction by the nonplanarity in the case of alpha substitution. Similarly, the aggregation tendency was lower in the case of alpha substitution. Among the fabricated coumarin-substituted manganese phthalocyanine donor layer and fullerene (C60) acceptor based photovoltaic heterojunction devices, the one containing 8 exhibited the best performance. The effect of the thickness of the active Pc layer on solar cell parameters has also been investigated. A nearly thickness independent open circuit voltage was observed.

4-Carboxymethyl-8-methyl-7-oxycoumarin substituted zinc, cobalt and indium phthalocyanines: electrochemical and photochemical properties

In this study, the novel tetra-substituted Zn(II)(3), Co(II)(4) and In(III)acetate (5) phthalocyanines were synthesized by cyclotetramerization reactions of 7-(2,3-dicyanophenoxy)-8-methylcoumarin-4-acetic acid (2) with corresponding metal salts. All the new compounds have been characterized by MALDI-TOF mass, FT-IR and UV-vis spectra, and elemental analysis as well. The electrochemical, in situ spectroelectrochemical and photochemical properties of tetra-substituted Zn(II), Co(II) and In(III)acetate phthalocyanines were also investigated.