Synthesis, characterization and electrochemical properties of novel metal free and zinc(II) phthalocyanines of ball and clamshell types (original) (raw)
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Coloration Technology, 2013
In this study, a novel metal-free phthalocyanine and three metallophthalocyanines carrying four 2-[2-(4-tertbutylphenoxy)ethoxy groups on the periphery were prepared by cyclotetramerisation of a dinitrile derivative in the presence of the corresponding divalent metal salts [zinc(II), cobalt(II), copper(II)]. These new phthalocyanine compounds have been characterised by infrared, 1 H and 13 C nuclear magnetic resonance and electrospray mass spectroscopies and elemental analysis. The electrochemical properties of the metalfree, zinc(II) and cobalt(II) phthalocyanines were investigated by cyclic voltammetry and differential pulse voltammetry methods. The cobalt complex showed a metal-based reduction process, while the metal-free and zinc(II) phthalocyanines showed ligand-based electron transfer processes. It has been found that the absorption spectra substantially depend on concentration. It has been shown that these changes are attributable to the association of the phthalocyanine molecule. The number of molecules in the associates and the equilibrium constants for this association are determined.
Polyhedron, 2008
4-[2-(Phenylthio)ethoxy]phthalonitrile 3 was synthesized by nucleophilic displacement of nitro group in 4-nitrophthalonitrile with 2-(phenylthio)ethanol 1. The metal-free phthalocyanine 4 was prepared by the reaction of a dinitrile monomer with 2-(dimethylamino)ethanol. Ni(II), Co(II), Cu(I) phthalocyanines 5, 7, 8 were prepared by reaction of the dinitrile compound with the chlorides of Ni(II), Co(II), Cu(I) in DMAE. Zn(II) phthalocyanine 6, was prepared by reaction of the dinitrile compound with the acetates of Zn(II) in DMAE. Electrochemical behaviours of novel metal-free, Co(II) and Zn(II) phthalocyanines were investigated by cyclic voltammetry, potential differential pulse voltammetry techniques. The new compounds were characterized by a combination of IR, 1H NMR, 13C NMR, UV–Vis, elemental analysis and MS spectral data.4-[2-(phenylthio)ethoxy]phthalonitrile 3 was synthesized by nucleophilic displacement of nitro group in 4-nitrophthalonitrile with 2-(phenylthio)ethanol 1. The metal-free phthalocyanine 4 was prepared by the reaction of a dinitrile monomer with 2-(dimethylamino)ethanol. Ni(II), Co(II), Cu(I)- phthalocyanines 5, 7, 8 were prepared by reaction of the dinitrile compound with the chlorides of Ni(II), Co(II), Cu(I) in DMAE. Zn(II)-phthalocyanine 6, was prepared by reaction of the dinitrile compound with the acetates of Zn(II) in DMAE. Electrochemical behaviours of novel metal-free, Co(II) and Zn(II) phthalocyanines were investigated by cyclic voltammetry, potential differential pulse voltammetry techniques. The new compounds were characterized by a combination of IR, 1H-NMR, 13C-NMR, UV-vis, elemental analysis and MS spectral data.
Synthesis and electrochemistry of new octa-substituted metal-free and metallophthalocyanines
Journal of Coordination Chemistry, 2015
The synthesis and characterization of metal-free (H 2 -Pc) and metal-containing (Zn, Co, and Cu) derivatives of a symmetrically octa-substituted phthalocyanine derived from 4,5-bis[2-(phenylthio) ethoxy]phthalonitrile were carried out by microwave irradiation. The electrochemical properties of the metal-free phthalocyanine 4 and metallophthalocyanine complexes 5 and 6 were investigated by cyclic voltammetry and differential pulse voltammetry. We have previously investigated the electrochemical properties of the tetra substituted 2-(phenylthio)ethoxy phthalocyanines. The reduction potential of the octa-substituted metal-free phthalocyanine shifted to more negative potential as a result of the electron donating of the 2-(phenylthio)ethoxy groups on the periphery compared to those of tetra substituted. The H 2 Pc and ZnPc demonstrated ligand-based electron transfer processes, while CoPc complex has a metal-based reduction process. Similar aggregation behavior was observed for octa-substituted phthalocyanines. The compounds were characterized using IR, 1 H NMR, 13 C NMR, elemental analysis, and MS spectral data.
Novel phthalocyanines bearing both quaternizable and bulky substituents
Dyes and Pigments, 2008
A new phthalonitrile derivative bearing dimethylaminoethylsulfanyl-and diethoxymalonyl-substituents at peripheral positions has been synthesized. Cyclotetramerization of this dinitrile in hexanol gave the desired cobalt(II) and zinc(II) phthalocyanines (4 and 5) with dimethylaminoethylsulfanyl and dihexoxymalonyl groups on periphery. Four dimethylaminoethyl groups of the former were quaternized to yield a water-soluble cobalt(II) phthalocyanine. Electrochemical redox properties of these phthalocyanines were investigated by cyclic voltammetry and applied chronocoulometry techniques.
The synthesis and electrochemistry of novel, symmetrical, octasubstituted phthalocyanines
Synthetic Metals, 2013
In this study, the preparation of new phthalocyanines with eight dialkylaminophenoxy or trialkylaminophenoxy substituents on periphery of the phthalocyanines was achieved by the cyclotetramerization of 1,2-dicyano-4,5-bis[3-(diethylamino)phenoxy]benzene (2). All of the synthesized compounds have been characterized by using elemental analysis, UV-vis, FT-IR, 1 H NMR and MS spectroscopic data. Aggregation behaviors of phthalocyanines were investigated in different solvents. The electrochemistry and in situ spectroelectrochemical properties of neutral and electrogenerated complexes were also characterized. All complexes coated on the working electrodes with electropolymerization process, which is a desired property for the functional materials for their practical applications. Dialkylamine groups on the substituents cause to electropolymerization of the complexes on the working electrode. Number of the substituents and the metal center of the complexes alter the character of the electropolymerization processes.
Molecules, 2020
Two novel phthalonitrile derivatives, bearing two hexyloxy groups and a benzodioxin (or a naphthodioxin) annulated ring, along with their corresponding metal-free phthalocyanines (H 2 Pc) were prepared. FT-IR, mass, electronic absorption, 1 H NMR, and 13 C NMR spectroscopy were employed for the characterization of all compounds. The effect of hexadeca substituents on the photophysical properties of metal-free Pcs was investigated. Photophysical properties of H 2 Pc were studied in tetrahydrofuran (THF). Fluorescent quantum yields of phthalocyanines (Pcs) were calculated and compared with the unsubstituted phthalocyanine. 1,4-Benzoquinone effectively quenched the fluorescence of these compounds in THF. Cyclic and square wave voltammetry methods were applied to metal-free phthalocyanines and Pc-centered oxidation and reduction processes were obtained.
Polyhedron, 2011
Mononuclear cobalt phthalocyanine (CoPc) substituted at the non-peripheral 8 and peripheral positions 9 with 1,1 0-binaphthyl-8,8 0-diol and ball-type dinuclear Co 2 Pc 2 substituted at the non-peripheral 10 and peripheral 11 positions with the same substituent are reported. The complexes with 1,1 0-binaphtholbridges were prepared from the corresponding phthalonitriles 4-7. The effects of the position of substituent on spectral, electrochemical and spectroelectrochemical properties of these complexes were also explored. The mononuclear complexes 8 and 9 exhibited one metal reduction, one ring reduction and one ring oxidation. The redox properties of the ball-type complexes 10 and 11 exhibited two reduction processes assigned to [(Co I Pc À2) 2 ] 2À /[(Co I Pc À3) 2 ] 4À (I), (Co II Pc À2) 2 /[(Co I Pc À2) 2 ] 2À (II) and one oxidation process assigned to [(Co III Pc À2) 2 ] 2+ /Co II Pc À2) 2 (III). The ball-type complexes are much easier to oxidize and more difficult to reduce than the corresponding monomers 8 and 9.
The synthesis of new metal-free, nickel, zinc, cobalt and copper phthalocyanines with four 6oxyquinoline groups on the non-peripheral position were prepared by cyclotetramerization of a novel 3-(quinolin-6-yloxy)phthalonitrile. All new compounds were characterized by the ways of IR, 1 H NMR, 13 C NMR and MS spectral data, all of which were compatible with the proposed structures. Electrochemical properties of metal-free, Ni(II) and Zn(II) phthalocyanines were investigated by using cyclic voltammetry and differential pulse voltammetry techniques. The metal-free phthalocyanine exhibits two reversible Pc ring-based one-electron reduction couples. The Ni(II) and Zn(II) phthalocyanines give very similar voltammetric responses with slightly potential shift due to the different metal center.
2016
Chapter 2: Literature Survey 2.1 Introduction 2.2 History and structural determination of phthalocyanines 2.3 General Applications of phthalocyanines 2.4 The synthesis of unsubstituted phthalocyanines 2.4.1 Metal-free phthalocyanine (H 2 Pc) 2.4.2 Metallated phthalocyanine (MPc) 2.5 The synthesis of substituted phthalocyanines 2.5.1 The synthesis of monosubstituted phthalonitriles 10 2.5.2 The synthesis of 3,6-disubstituted phthalonitriles 12 2.5.3 Axially Substituted Phthalocyanines 13 2.6 Electrochemical studies tetrakis(pentafluorophenyl)borate, [ n Bu 4 N][B(C 6 F 5) 4 ], 22
Dyes and Pigments, 2011
A new class of soluble unsymmetrically substituted metallophthalocyanines (M ¼ Zn, Ni, Co) bearing a crown ether and six alkylthio substituents was synthesized and their electrochemical and spectroelectrochemical properties studied. Cyclic and square wave voltammetry revealed well-defined ligand-based oxidation and reduction processes within the complexes. Assignment of the redox processes was performed by in-situ spectroelectrochemical measurements. The disappearance of the redox processes for the monomeric species and the observation of new waves indicated that intermolecular dimer formation occurred during the potentiometric titration of the complexes with K þ and Na þ ions.