Özer Bekaroğlu

Phthalocyanines as Sensitive Materials for Chemical Sensors

This paper provides a review of phthalocyan- ines suitable for the development of chemical sensors. Phthalocyanines may be utilized for different types of chemical sensors, including in particular electronic conductance sensors [such as semiconductive, field-effect transistor (FET), solid-state ionic and capacitance sensors], mass-sensitive sensors utilizing a quartz crystal microbalance (QCM) and surface acoustic-wave (SAW) sensors, and optical sensors. The phthalocyanines used are discussed in terms of their physical and chemical properties, as well as their sensitivity, selectivity and reversibility towards the detection of NO2 and organic solvent vapours. The interaction mechanism between phthalocyanine films and analyte molecules is also discussed.

Synthesis, characterization and electrochemistry of novel differently octasubstituted phthalocyanines

Abstract We describe the complete synthesis of differently substituted multifunctional metallo phthalocyanines (MPcs) (M=Ni, Zn, Co) bearing four 2′-aminophenylsulfanyl or 2-aminophenoxy moieties and four chloro atoms on peripheral positions. The synthesis started from the corresponding anhydrous metal salts and differently substituted [4-(2′-aminophenylsulfanyl)-5-chlorobenzene-1,2-dicarbonitrile] (2a) and [4-(2-aminophenoxy)-5-chlorobenzene-1,2-di-carbo nitrile] (2b), and the products were separated by HPLC. These multifunctional amino substituents serve as strong binding sites for further reactions after phthalocyanine formation, such as Schiff-bases, and provide solubility of the phthalocyanines in organic solvents (THF, CHCl3 and CH2Cl2). The newly synthesized compounds have been characterized by elemental analysis, FTIR, 1H NMR, MS (EI and FAB), UV–Vis and atomic absorption spectroscopy. Electrochemical studies reveal that CoPc (6a) has two metal and four ligand-based redox processes while NiPc (4a) and ZnPc (5b) show three ligand-based reduction processes.

The Synthesis and Complex Formation of Swe New Substituted Amino and Diaminoglyoximes

Abstract The following substituted amino and diaminoglyoximes have been synthesized: N-(phenyl)aminoglyoxime, N-(1-naphthyl)aminoglyoxime, N-(2-naphtyl)aminoglyoxime, 1,1′-biphenyl-4-amino-4′-aminoglyoxime, 1,1′-biphenyl-4,4′-bis(aminoglyoxime), N, N′-bis(1-naphthy1)diaminoglyoxime, N, N′-bis(2-naphthyl)diaminoglyoxime. Their complexes with Cu(II), Ni(II), Co(II), Zn(II), Cd(II) and UO2(VI) have been isolated. The structures of these new compounds are proposed on the basis of elemental analysis, n.m.r., i.r., u.v.-visible spectral data.

Novel crown ether-substituted phthalocyanines

Abstract A novel macrocycle has been synthesized from 4′-(α-bromoacetyl)benzo-15-crown-5, 4-nitrophthalonitril and diethyl malonate; its cyclotetramerization gives Cu(II), Co(II) and Pd(II) phthalocyanines (Pcs) with four benzo-15-crown-5 substituents on the periphery. The effects of alkali metal cations with these Pcs has been investigated through the changes in the visible spectra. The newly synthesized compounds have also been characterized by elemental analyses, IR, 1 H NMR.

Synthesis and characterization of novel symmetrical phthalocyanines substituted with mono- or bi-macrocycles

Abstract A new generation of soluble metallophthalocyanine derivatives (5a, 5b, 6a, 6b, 7b, 8b and 8b·2KSCN) bearing four 14-membered [1,4,8,11] dioxadiaza macrocycles, 14-membered [1,4,8,11] diazadithia-macrocycles or 14-membered [1,4,8,11] diazadithia-macrocycles fused to a 15-membered crown-ether have been prepared by cyclotetramerization of the newly synthesized dicyano macrocycle (3a, 3b and 4b) in the presence of appropriate metal salts in non-aqueous solvents. The N-tosylated derivatives are extensively soluble in apolar solvents. The interaction of the alkaline metal salts with the crown-ether groups of the complex 8b resulted in products of less solubility. Elemental analysis results and IR, UV–Vis, 1H NMR, mass spectral data on the newly synthesized intermediates and all phthalocyanines are in accordance with the proposed structures.

Electrochemistry of lutetium crowned ether diphthalocyanine films

Films of crown-ether substituted diphthalocyanine of lutetium (CR-Pc2Lu) have been studied by cyclic voltammetry. In contact with K+ or Na+ aqueous electrolyte, two reversible one-electron steps lead to the formation of the orange cation CR-Pc2Lu+ and to the blue anion CR-Pc2Lu−. With other alkali metal cations, the irreversibility of both steps increases in the order K+, Na+ ⪡ Li+ < Rb+, Cs+. In acid medium (HCl or HClO4), voltammetry cannot be performed in the absence of alkali cation added simultaneously to the solution, and destruction of the films occurs. In contact with a KCl + HCl or a KClO4 + HClO4 solution, disproportionation of CR-Pc2 Lu proceeds and a two-electron voltammetric peak takes the place of the two one-electron steps. A E-pH “Pourbaix” diagram is established.

Synthesis and Characterization of Octakis (hydroxyethylthio)-substituted Phthalocyanines

The new metal-free phthalocyanine 2 and phthalocyaninatometals 3–5 (M = Ni, Co and Zn) carrying eight hydroxyethylmercapto groups on peripheral positions have been synthesized from 1,2-bis(hydroxyethylmercapto)-4,5-dicyanobenzene in the presence of a suitable anhydrous metal salt [NiCl2, CoCl2 or Zn(O2CMe)2] or hydroquinone. Zinc (II) phthalocyaninate reacted with palladium(II) salt to form complexes with a phthalocyanine (metal ratio of 1:4). The electrical conductivity of the phthalocyanines 2, 3, 5, 5a are in the semiconductor range.

Novel two-fold-macrocycle-substituted phthalocyanines

New metallophthalocyanines (M = Cu or Ni) substituted in peripheral positions with four 14-membered tetraaza macrocycles each attached to a 15-membered crown ether have been prepared in a multi-step reaction sequence. The N-tosylated derivatives are extensively soluble in apolar solvents and form adducts with alkali-metal cations. Detosylation of the macrocyclic aza groups provides donor sites for binding transition-metal ions (e.g. NiII) which leads to pentanuclear water-soluble complexes.

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 AND PROPERTIES OF NEW PHTHALOCYANINES WITH TERTIARY OR QUATERNARIZED AMINOETHYLSULFANYL SUBSTITUENTS

Abstract Metal-free- and metallo-phthalocyanines (M = Ni or Zn) carrying four dimethylaminoethylsulfanyl-or trimethylaminoethylsulfanyl- groups on peripheral positions have been synthesized from the corresponding phthalonitrile derivatives in the presence or the absence of the anhydrous metal salt [NiCl2 or Zn(CH3COO)2]. The new compounds have been characterized by elemental analyses, IR, NMR, and electronic spectroscopy and mass spectra. Phthalocyanines with quaternarized amino groups are soluble in aqueous solution over a wide pH range and these molecules are present as aggregated species in solution as confirmed by the blue shift of Q bands in their electronic spectra.