Nickel Phthalocyanine Complexes Research Articles

The Study of Interaction Activity of Nickel (ll) Phthalocyanine Complex Bearing Tetra Substituted Phenoxy-3-Methoxybenzoic Acid Groups with DNA

Nickel phthalocyanine complex containing 3-methoxybenzoic acid groups was acquired and specified by way of Fourier Transform Infrared, NMR and UV-Visble spectroscopy procedures. Interaction of PcNi with the DNA molecule was examined via electronic absorption spectra, fluorescence spectra, melting point, viscosity, and the electrophoresis technics, respectively. The interaction activity of PcNi against the DNA was examined by way of absorption spectra titrations and the fluorescence spectra, farther by conducting melting point, viscosity procedures in the buffer of a pH 7.02. The obtained outcomes from these methods demonstrated that PcNi indicated substantial binding affinity to the DNA via intercalating by Kb of 1.31 x 106 m-1. Further, the interacting activity of PcNi on the DNA was analyzed by which electrophoresis technique and this procedure indicated that PcNi complex exhibits strong binding affinity on the DNA.

Synthesis, Spectral, and Fluorescence Studies of Fluorophenyl Methoxy Substituted Nickel Phthalocyanine Complex.

The synthesis, characterization, spectral, fluorescence properties of bis(4-fluorophenyl)-methoxy substituted nickel phthalocyanine were reported for the first time. The new compound has been characterized by elemental analysis, UV-Vis, FT-IR, 1H-NMR and mass spectra. The aggregation behaviour of this compound was investigated in the different solvent and concentrations of in CHCl3. Phthalocyanine complex did not show any aggregations. The fluorescent properties of the compound in five different solvents such as CHCl3 CH2Cl2 THF, DMF, DMSO were explained. Phthalocyanine complex gave the highest fluorescence quantum yield in CHCl3 and the lowest fluorescence quantum yield in DMSO.

Light assisted nickel(II) grafted-g-carbon nitride molecular hybrid promoted hydrocarboxylation of olefins with CO2 at atmospheric pressure condition

An efficient photocatalytic method was developed for the hydrocarboxylation of olefins to corresponding acids using carbon dioxide assisted by a molecular hybrid photocatalyst consisting of nickel phthalocyanine complex grafted to graphitic carbon nitride support (NiPc/g-C3N4) under ambient temperature and pressure conditions. The reaction is found to be regioselective in nature as aromatic olefins i.e. styrenes and its derivatives afforded α-carboxylated products; whereas aliphatic olefins yielded terminal acids selectively in moderate-to-good yields. The DFT calculations suggested the higher efficiency of the hybrid photocatalyst as compared to its individual components. Based on the electrochemical measurements and adsorption behaviour of the CO2 on the catalyst and corresponding bond distances calculated by DFT, a possible mechanism is proposed. Furthermore, triethylamine was used as a sacrificial donor that provided the required electrons to complete the redox cycle of the reaction.

Single walled carbon nanotubes functionalized with nickel phthalocyanines: effects of point of substitution and nature of functionalization on the electro-oxidation of 4-chlorophenol

In this work we report on electrochemical behavior of nickel phthalocyanine derivatives tetrasubstituted peripherally and non-peripherally with hydroxy and used to modify single walled carbon nanotubes. Nickel phthalocyanine complex octasubstituted at the peripheral positions with hydroxy groups was also used to modify single walled carbon nanotubes. Nickel phthalocyanine complex tetrasubstituted with amino groups at peripheral position was covalently and non-covalently linked to single walled carbon nanotubes. All the conjugates of nickel phthalocyanine derivatives with single walled carbon nanotubes were used for the electro oxidation of 4-chlorophenol. The nickel phthalocyanine octabsubstituted with hydroxy groups at the non-peripheral positions gave the best current response and the best resistance against electrode fouling for the oxidation of 4-chlorophenol.

4-acyloxy- and 4-acylaminophthalonitriles and phthalocyanines based thereon

Reactions of 4-hydroxy- and 4-aminophthalonitriles with substituted benzoyl chlorides gave the corresponding N- and O-benzoyl derivatives, and the latter were used to obtain copper and nickel phthalocyanine complexes. Effect of the substituents in the latter on their electronic absorption spectra was studied. The obtained complexes were found to undergo association in organic solvents.

Electrochemical properties of benzylmercapto and dodecylmercapto tetra substituted nickel phthalocyanine complexes: Electrocatalytic oxidation of nitrite

Nickel tetrakis(benzylmercapto)phthalocyanine (NiTBMPc) and nickel tetrakis(dodecylmercapto)phthalocyanine (NiTDMPc) complexes were synthesized and their spectral and electrochemical properties reported. The CV showed four or five redox processes for NiTBMPc and NiTDMPc, respectively. For the first time, spectroelectrochemistry gave evidence for the formation of Ni II/Ni I process in a NiPc complex. The rest of the processes were ring based. The NiTBMPc complex was successfully deposited on both gold and glassy carbon electrodes by electropolymerisation while NiTDMPc complex was deposited on gold electrode only. The films were electro-transformed in aqueous 0.1 M NaOH solution to the O–Ni–O oxo bridged form. The modified electrodes were characterized using electrochemical impedance spectroscopy and the results showed typical behavior for modified electrodes. Electrodes with poly-Ni(OH)Pcs films exhibited higher charge transfer resistance values, R p than their corresponding poly-NiPcs films counterparts. All the modified electrodes showed improved catalytic activities than the unmodified electrodes towards nitrite ions electrooxidation. Better catalytic activities were observed for the modified electrodes when they were transformed to O–Ni–O oxo bridge form. All the modified electrodes exhibited high resistance to electrode surface passivation.

Nickel Phthalocyanine Complex Encapsulated into Nanopores of Faujasite Zeolite

Nickel(II) phthalocyanine complexes encapsulated in X-type Zeolite were constructed by the ‘Ship-in-bottle’ synthesis, whose characterizations were performed by fluorescent X-ray, UV-vis, reflectance, and ESR spectroscopic methods. UV-vis and Reflectance spectra of NiPc-Na+-X suggested that the Pc ring was synthesized. Solid state ESR spectrum of NiPc-Na+-X gave characteristic pattern for organic radical species. Catalytic oxidation reactivity of the NiPc-Na+-X in homogeneous reaction have been studied for organic substrate in the presence of H2O2.

Nickel Tetraaminophthalocyanine Based Films for the Electrocatalytic Activation of Dopamine

AbstractA novel electrode material was obtained by two consecutive procedures: (i) the electropolymerization of NiTAPc in DMF via the electro‐oxidative N–N coupling of the amino groups, to achieve a film denoted poly‐NiTAPc, followed by (ii) the electrochemical transformation of the poly‐NiTAPc film in alkaline aqueous solution to form the interconnected ONiO oxo bridges. The obtained film is then denoted poly‐NiTAPc(OH). For the first time the electropolymerized poly‐NiTAPc coating shows a clear electrocatalytic activity towards Dopamine (DA) redox process, either as prepared or upon its electrochemical transformation in alkaline solution. Furthermore it clearly appears that poly‐NiTAPc(OH) film exhibits a much larger electrocatalytic behavior than the as‐prepared poly‐NiTAPc coating. This shows unambiguously the beneficial effect of the changes in the staking structure of the nickel phthalocyanine complexes upon the electrochemical treatment of the film in alkaline solution. It should be emphasized here that the increase in the oxido‐reduction currents related to DA on both films is not to be associated with any changes in the geometrical electrode area. This novel kind of material could present some interesting potentialities for a highly sensitive detection of others neurotransmitters.

Synthesis and characterization of unsymmetrically substituted dienophilic nickel phthalocyanines for Diels-Alder reactions

A general synthesis of unsymmetrically substituted dienophilic nickel phthalocyanines is described. The desired nickel phthalocyanine complexes [3,4,10,11,17,18-hexakis(2-ethyl-hexyloxy)tribenzo(b,g,i]-24,27-di-hydro-24,27-epoxynaphthalo[q]porphyrazinato]nickel(II) (4) and dodeca alkoxy-substituted PcNi (5) were synthesized using a statistical approach by the condensation of 1,2-dicyano-4,5-bis(2-ethylhexyloxy)benzene (1) or 1,2-dicyano-3,4,5,6-tetrakis(2-ethylhexyloxy)benzene (2) and 6,7-dicyano-1,4-dihydro-1,4-epoxy-1,4-dimethylnaphthalene (3) in the presence of nickel(II) acetate. Reaction of 4 or 5 with tetraphenyl-cyclopentadieneone (9) lead to the phthalocyanine-tetracyclone adducts 10 and 11, respectively, which are precursors for intermediate adducts 12 and 13 containing isobenzofuran moiety as diene subunits. The dimer 14 was synthesized from 4 and the isobenzofuran intermediate 12. Dehydrogenation of the Diels-Alder product 14 to the fully conjugated derivative 15 was carried out successfully with p-toluenesulfonic acid.

A Supported Nickel Phthalocyanine Complex as a Selective Catalyst for the Production of Styrene

A nickel phthalocyanine complex (NiPc) supported on bentonite clay (Bihar, India) was used as a selective catalyst for the dehydrogenation of ethylbenzene to styrene. Maximum activity was observed for the catalyst sample containing 1.0 wt% NiPc/bentonite. A higher loading of complex (> 1.4 wt%) exhibited no activity and resembled polycrystalline NiPc. The texture of the studied catalyst and the mode of surface dispersion of the supported NiPc were investigated through the adsorption of N2 and O2, respectively. The activity of the diluted samples could be attributed to the presence of separate highly dispersed molecules of NiPc on the bentonite surface without having a marked effect on its pore system for most active samples. The selectivity towards styrene was found to depend strongly on the NiPc surface area and the degree of dispersion. The activity was a function of the whole structure including modifications of both acid sites through different interactions and of the pore system through a penetration mechanism.

Transition metal phthalocyanine and porphyrin complexes as catalysts for the polymerization of alkenes

Vanadium phthalocyanine and porphyrin complexes, in conjunction with methylaluminoxane (MAO) or EtAlCl2 cocatalyst, have been found to catalyze the homopolymerization of ethene. In addition, the copolymerization of ethene with propene and 1-decene was achieved with the vanadium phthalocyanine complex and MAO. Nickel phthalocyanine complex was also found to catalyze the polymerization of ethene in the presence of MAO. However, only dimerization was observed when EtAlCl2 was used as the cocatalyst.Key words: phthalocyanine, porphyrin, polymerization, copolymerization, ethene, propene, 1-decene.

“Synthetic metals” based on nickel(II) 2,9,16,23-tetrahalo-substituted phthalocyanine derivatives

Symmetrically nickel(II) 2,9,16,23-tetrahalo-substituted phthalocyanine complexes, NiPTX (where X=–F, –Cl, –Br, and –I) are prepared in pure state. Elemental, electronic, IR, magnetic susceptibility measurements, X-ray diffraction and TGA studies are carried out on the above complexes both before and after iodine doping. Electrical conductivity of the nickel phthalocyanine derivatives depends on the nature of the substituent and found to show ∼10 3 times improved conductivity in comparison to parent nickel phthalocyanine complex. It is interesting to note that substitution and iodine doping showed remarkably high ∼10 9 times increased electrical conductivity in comparison to nickel phthalocyanine. This may be due to the decrease in the metal–metal bond distance, increase in the approach of the ideal eclipsed system or due to the combined effects of the above factors.

Electrochemical study of antioxidants at a polypyrrole electrode modified by a nickel phthalocyanine complex. Application to their HPLC separation and to their FIA system detections

A polypyrrole electrode modified with a tetrasulfonated nickel(II) phthalocyanine complex (GCE/PPy/NiPcTs) was used as amperometric electrochemical detector in a flow injection system, in order to determine some antioxidants in foods. The lather were separated by HPLC and detected at the modified electrode. Previous investigations carried out in our laboratory employed this electrode and cyclic voltammetry (CV), obtaining excellent results, due to an electrocatalytic effect on the oxidation of certain alimentary antioxidants, such tert-butylhydroquinone (TBHQ), 3- tert-butyl-4-hydroxyanisole (BHA) and propylgallate (PG). In order to obtain good separation, the chromatographic conditions were optimised. The geometry of the flow injection analysis (FIA) circuit and the reproducibility of the results were also optimised and, finally, the linear relationship between the signal and the concentration was verified. The proposed procedure is more precise and accurate than the conventional voltammetry methods. These results offer new analytical possibilities to this type of modified electrodes. The developed methods were applied to the determination of these antioxidants in commercial food.

Voltammetric determination of the phenolic antioxidants 3-tert-butyl-4-hydroxyanisole and tert-butylhydroquinone at a polypyrrole electrode modified with a nickel phthalocyanine complex

The voltammetric behaviour of the antioxidants 3-tert-butyl-4-hydroxyanisole (BHA) and tert-butylhydroquinone (TBHQ), at a polymer electrode modified with nickel phthalocyanine as electron mediator, is described, and an electroanalytical method for the determination of these antioxidants based on their electrochemical oxidation on the modified electrode is proposed. Cyclic voltammograms showed well-defined oxidation peaks slightly shifted towards less positive potentials with respect to those obtained at the platinum disk electrode for both antioxidants. The peak currents measured at the modified electrode are considerably higher than those obtained at the unmodified electrode. A scan rate of 100 mV s −1, a minimum methanol percentage of 0.5% and a 0.1-M Britton-Robinson medium were chosen as working conditions. The obtained results suggest that the BHA oxidation produces the TBHQ reduction product. This product is oxidised during the second cyclic scan, to generate the mentioned TBHQ as final product. These studies also reveal that sensitive response for both antioxidants can be obtained by using the differential pulse voltammetry (DPV) technique. Responses observed are dependent on the nature of the control solution (% methanol and pH) and the nature of voltammetric conditions (potential amplitude, Δ E, and scan rate, v b). These factors have been modified in order to find the best analytical conditions. The mutual interferences between both antioxidants and the measurement reproducibility were tested. Using cyclic voltammetry (CV) and differential pulse voltammetry, BHA and TBHQ linear calibration graphs were obtained. The detection limits were 2.1 ppm for both when CV was used, and 18.7 ppm (BHA) and 1.23 ppm (TBHQ) for DPV. The developed methods were applied to the determination of BHA in spiked glaze biscuits and TBHQ in spiked mushroom cream.

Biodegradation of azo and phthalocyanine dyes by Trametes versicolor and Bjerkandera adusta

Eighteen fungal strains, known for their ability to degrade lignocellulosic material or lignin derivatives, were screened for their potential to decolorize commercially used reactive textile dyes. Three azo dyes, Reactive Orange 96, Reactive Violet 5 and Reactive Black 5, and two phthalocyanine dyes, Reactive Blue 15 and Reactive Blue 38, were chosen as representatives of commercially used reactive dyes. From the 18 tested fungal strains only Bjerkandera adusta, Trametes versicolor and Phanerochaete chrysosporium were able to decolorize all the dyes tested. During degradation of the nickel-phthalocyanine complex, Reactive Blue 38, by B. adusta and T. versicolor respectively, the toxicity of this dye to Vibrio fischeri was significantly reduced. In the case of Reactive Violet 5, a far-reaching detoxification was achieved by treatment with B. adusta. Reactive Blue 38 and Reactive Violet 5 were decolorized by crude exoenzyme preparations from T. versicolor and B. adusta in a H2O2-dependent reaction. Specific activities of the exoenzyme preparations with the dyes were determined and compared to oxidation rates by commercial horseradish peroxidase.

Preparation of a polypyrrole electrode modified with a nickel phthalocyanine complex. Application to the determination of an antioxidant (propylgallate) in foods

In this paper a study of the electrocatalytic oxidation of propylgallate (PG) by using a polypyrrole electrode modified with tetrasulfonate nickel (II) phthalocyanine complex (Pt/PPy/NiPcTs) was carried out. Several parameters of this polymeric electrode, such as: (a) its stability in hydroorganic solution, by using an indium tin oxide (ITO) electrode and spectrophotometry; and (b) its thickness using electrochemical techniques, have been studied. In addition, several parameters affecting the PG voltammetric peak, such as pH, methanol water ratio, potential scan rate and analyte concentration, were considered. Finally, the developed method was applied to the determination of PG in spiked potato flakes and cornflakes, showing its validity.