Cobalt Phthalocyanine Complexes Research Articles

Electrochemical detection of prostate specific antigen in the presence of an aptamer and composites of cobalt phthalocyanine-exfoliated graphite

This work focuses on the development of biosensor and their use for the detection of prostate specific antigen (PSA). The three cobalt phthalocyanine (CoPc) complexes, exfoliated graphite (EG), and an aptamer are used to make a probe for PSA detection. Each CoPc complex is π-π stacked onto the EG to form EG-CoPc(π-π) hybrid which was then used to modify a glassy carbon electrode (GCE). EG and CoPc were also used to modify the GCE sequential (seq) with CoPc on top to give GCE-EG-CoPc(seq). For the detection PSA, PSA specific aptamer was either adsorbed or covalently linked to the modified electrodes. Electrochemical impedance spectroscopy (EIS) and differential pulse voltammetry (DPV) were the techniques used for the detection of PSA. The electrodes were found to be selective in the presence of bovine serum albumin, glucose and cysteine and were stable when 50 DPV scans were run. The electrodes showed good % recovery when human serum was spiked with different PSA concentrations.

The use of carbon-based nanomaterials conjugated to cobalt phthalocyanine complex in the electrochemical detection of nitrite

The use of carbon-based nanomaterials conjugated to cobalt phthalocyanine complex in the electrochemical detection of nitrite

Assessing in vitro anti-cancer efficacy of sulfonated water-soluble phthalocyanine on breast and prostate cancer cells

Since cancer is one of the leading causes of death worldwide, the development of new anticancer drugs has become important. Phthalocyanines (Pcs) as anticancer agents have attracted particular attention in recent years. Especially water-soluble sulfonated phthalocyanines have been used consistently for both the diagnosis and treatment of many different types of cancer, such as small lung tumors. Motivated by these facts, since the anti-cancer activity of sulfonated water-soluble cobalt phthalocyanine in prostate and breast cancer without photoactivation is not known before, we aimed to investigate the in vitro anti-cancer effectiveness (cyto- and genotoxic effect) of alpha-substituted water-soluble cobalt phthalocyanine (WS-CoPc) complex on prostate and breast cancer cells for the first time. For this purpose ROS production, cell death, and DNA damage levels, changes in nuclear and cell morphology, and the expression of apoptosis and ROS-related genes were determined. WS-CoPc exhibited anti-cancer effects with cytotoxic and genotoxic features in both prostate and breast cancer cells also the anti-cancer efficacy is more prominent in prostate cancer cells. Therefore our results demonstrated that this Pc has high cytotoxic and genotoxic effects, especially in prostate cancer cells in vitro and further studies are needed to reveal the current anticancer potential of this Pc without photoactivation.

Novel peripheral and non-peripheral oxobenzo[d]thiazol substituted cobalt phthalocyanines: Synthesis, electrochemistry, spectroelectrochemistry, electrocatalytic hydrogen production in alkaline medium

• A oxobenzo[d]thiazol substituted cobalt phthalocyanines was synthesized . • The redox properties of CoPcs were illuminated. • GO/CoPcs catalysts showed low overpotential of 330 mV at 10 mAcm −2 in alkaline HER. • GO/CoPcs exhibited ∼ 53 times higher catalytic current density than bare GCE. In this study novel oxobenzo[d]thiazol substituted cobalt phthalocyanine complexes were synthesized and characterized by FT-IR, NMR, UV–vis spectroscopy, and mass spectrometry. The redox properties of peripheral and non-peripheral substituted CoPc complexes were determined and compared via electrochemical characterization. The reduction–oxidation transitions of the metal and the ring were recorded with in-situ spectroelectrochemical measurements. Electrocatalytic activity of complexes were investigated in alkaline medium for hydrogen evolution reaction. The CoPc complexes exhibited excellent electrocatalytic activity in presence of graphene oxide. The GO/3N-CoPc and GO/4N-CoPc displayed low overpotential of 330 mV at 10 mA cm −2 with Tafel slope of 64 mV dec −1 , which superior in comparison with the CoPc (overpotential of 497 mV at 10 mA cm −2 ). Moreover, GO/3N-CoPc and GO/4N-CoPc electrocatalysts exhibited ∼ 53 times higher catalytic current density than bare GCE.

Europhtal: An industrial cobalt phthalocyanine complex as the efficient catalyst for synthesis of thioamides by one‐pot reaction of mercaptans and amines

AbstractThe potential of industrial cobalt phthalocyanines in the synthesis of thioamides is reported. A mixture of an industrial sulfonated cobalt phthalocyanines known as Co[(SO3Na)2,3Pc] (Europhtal catalyst additive 8020) is introduced as an efficient catalyst capable of converting benzyl thiols to synthetically valuable thioamides by reaction with amines and DMSO. In this procedure, different primary and secondary amines also heterocyclic amines were successfully converted into benzothioamides in high yields. This simple, one‐pot three‐component conversion method is scalable and provides efficient and practical route to the synthesis of diverse benzothioamides.

Solvothermal modification of graphitic C3N4 with Ni and Co phthalocyanines: Structural, optoelectronic and surface properties

Nanocomposites for photocatalytic applications were obtained by alchothermal modification of g-C3N4 with cobalt(ii) and nickel(ii) phthalocyanine complexes. The nanocomposites demonstrated higher photocatalytic activity than the bare matrix and stability under actinic irradiation. In the optoelectronic structure of the composites, the Eg value of the g-C3N4 matrix increased to 3.05 eV, while for MPc agents, it decreased from 1.96 to 1.82 eV.

Photoinduced Absorption Spectra of Donor–Acceptor Systems Based on Cobalt(II) and Manganese(III) Phthalocyanine Complexes with Femtosecond Time Resolution

Photoinduced Absorption Spectra of Donor–Acceptor Systems Based on Cobalt(II) and Manganese(III) Phthalocyanine Complexes with Femtosecond Time Resolution

Electrochemical Polymerization of a Carbazole‐Tethered Cobalt Phthalocyanine for Electrocatalytic Water Oxidation

AbstractThe four‐electron oxidation of water (2H2O→O2+4H++4e−) is critical for artificial photosynthesis. In nature, this reaction is efficiently catalyzed by photosystem II via cooperative catalytic centers and charge transporters. However, the integration of water oxidation catalysts and charge transporters in artificial systems remains challenging. In this report, a function‐integrated water oxidation catalyst produced by the electrochemical polymerization of a cobalt phthalocyanine complex bearing carbazole moieties is described. The monomer complex, Co(czPc) (H2czPc=tetrakis(9H‐carbazole‐9‐ethoxy)phthalocyanine), was synthesized and characterized by elemental analysis, matrix‐assisted laser desorption/ionization mass spectrometry, and Fourier transform infrared and ultraviolet‐visible spectroscopy measurements. The electrochemical polymerization of Co(czPc) was confirmed using cyclic voltammetry measurements and yielded poly‐Co(czPc) on the surface of a glassy carbon electrode. Poly‐Co(czPc) showed excellent charge‐transport ability and superior electrocatalytic water oxidation performance to that of the corresponding nonpolymeric system.

Improving the lifetime of hybrid CoPc@MWCNT catalysts for selective electrochemical CO2-to-CO conversion

Molecular hybrid catalysts, such as cobalt(II) phthalocyanine (CoPc) complexes anchored to multi-walled carbon nanotubes (MWCNTs), provide selective CO2 conversion toward CO with high current densities, exceeding 0.1 A cm−2 in microfluidic or zero-gap (membrane) electrolyzers. However, the practicality of CO2 electroreduction is essentially determined by the catalyst stability against mechanical and (electro)chemical degradation. Here, we report a new mechanism for the observable degradation of the CoPc@MWCNT hybrid catalyst. Even at moderate CO2 reduction potentials, the demetalation of CoPc complexes is induced by a reduction of iron (Fe) species, which can contaminate commercially available MWCNTs or solvents used for catalyst preparation. Minimization of Fe contamination leads to a substantial improvement in the CoPc@MWCNT catalyst lifetime, with the faradaic efficiency of CO formation decreasing from 98% to 96% (by only 2%) after 95 h of electrolysis. Thus, careful purification of hybrid catalyst materials is required to maintain initial levels of catalyst performance during long-term operation.

Molecular fluorinated cobalt phthalocyanine immobilized on ordered mesoporous carbon as an electrochemical sensing platform for sensitive detection of hydrogen peroxide and hydrazine in alkaline medium

• Molecular CoPcF16 is anchored on CMK-3. • The interaction between CoPcF16 and CMK-3 is investigated. • CMK-3-CoPcF16 exhibits high electrocatalytic activity. • Sensitive detection of H 2 O 2 and hydrazine is achieved. Non-precious molecular cobalt phthalocyanine (CoPc) complexes have been considered to be promising electrocatalysts due to diversity of substituents and carbon supporting matrixes. Here, we report a highly dispersed fluorinated CoPc (CoPcF16) molecule electrocatalyst immobilized in ordered mesoporous carbon CMK-3 (CMK-3-CoPcF16) via π-π interaction. The molecular electrocatalyst is characterized by X-ray photoelectron spectroscopy, Raman spectrum, electronic paramagnetic resonance, scanning electron microscopy, transmission electron microscopy and electrochemical impedance spectroscopy. The combination of fluorine substituents and high loading capability of CMK-3 increase the solubility of CoPc, suppress aggregation, and thereby enhance the electrocatalytic performance. As a result, the CMK-3-CoPcF16 modified electrode shows high electrocatalytic activity towards the oxidation of hydrogen peroxide and hydrazine. CMK-3-CoPcF16 hybrid is successfully presented as an electrochemical sensing platform for sensitive detection of H 2 O 2 and hydrazine with a detection limit of 0.03 and 0.2 µM, respectively.

Construction of organic–inorganic hybrid photoanodes with metal phthalocyanine complexes to improve photoelectrochemical water splitting performance

The modification of cobalt phthalocyanine complexes on BiVO4 could promote the charge carrier migration and accelerate the water oxidation kinetics, thus significantly enhancing the photoelectrochemical water splitting.

High quantum yield photochemical water oxidation using a water-soluble cobalt phthalocyanine as a homogenous catalyst.

We demonstrated high catalytic activity (TON = 670, TOFmax = 2.7 s-1) of a water-soluble cobalt phthalocyanine complex (CoPcTS, PcTS = phthalocyaninetetrasulfonate) for visible light-driven photochemical water oxidation and investigated its reaction mechanism by electrochemical and spectroscopic measurements.

Novel amide coupled phthalocyanines: Synthesis and structure-property relationship for electrocatalysis and sensing of hydroquinone

• Amide bridged CoPc macrocyclic dyes were prepared and elucidated the structure using physico-chemical techniques. • The amide CoPc was deposited on glassy carbon electrodeandcharacterized with SEM and electrochemical techniques. • Among different CoPcR 4 /GCE electrode, CoTAMFCAPc/GCE showed better sensitivity for QH 2 with lower LOD. • CoTAMFCAPc/GCE is stable and selective for QH 2 and has been applied for the detection of QH 2 in real samples. Analogs of amide bridge cobalt phthalocyanine complexes with different peripheral substituents have been prepared with good yield and these dyes possess dark green colour. These phthalocyanine complexes are characterized by elemental analysis, absorption spectra, infrared spectroscopy, mass and electrochemical methods. An attempt has been made to understand the structure–property relationship of these molecules for electrochemical properties. Hence, uniform and thin film of amide phthalocyanine ( Pc ) complex was administered on glassy carbon electrode (GCE) surface and scanning electron microscopy (SEM) images displayed the uniform distribution of the macrocycle on the surface. The modified electrodes are found to be electroactive and the Ohmic/Faradic surface response of the film is studied using electrochemical impedance spectroscopy (EIS). The formal Co(II)/(I) redox behavior of the substituted phthalocyanines have been explained using Hammett parameter. The electrode surface modified with terminal amide bridged Co-N4 macrocyclic complexes were applied for the sensing of hydroquinone (QH 2 ). An attempt was made to understand the influence of structure and functional groups on the electrocatalytic activity. Cyclic voltammetry (CV) displayed significantly increasing current trend for QH 2 in the quantitative range 200–2200 nM at the furan containing amide phthalocyanine (CoTAMFCAPc) electrode with a low limit of detection (LOD) of 65 nM. Further, the chronoamperometric analysis showed better linear response for QH 2 in 170–1530 nM range with LOD 56 nM at GCE/CoTAMFCAPc electrode compared to other molecules. The fabricated GCE/CoTAMFCAPc electrode demonstrated good stability and selectivity for QH 2 in presence of molecules with similar structure which co-exist along with QH 2 . GCE/CoTAMFCAPc electrode can be employed for practical application and produced superior recovery values for QH 2 .

Phosphorous doped g-C3N4 supported cobalt phthalocyanine: An efficient photocatalyst for reduction of CO2 under visible-light irradiation

The photoreduction of the green-house gas CO2 into carbon monoxide (CO) is a growing process due to the use of CO for the production of methanol in the Fischer-Tropsch process and the synthesis of many of the bulk chemicals. Here, we have synthesized phosphorous doped graphitic carbon nitride (P-g-C3N4) sensitized by the cobalt phthalocyanine complex for the molecular reduction of CO2 into CO under visible-light irradiation—the doping of phosphorous improved the stability as well as the harvesting of the visible region. The CoPc@P-g-C3N4 hybrid photocatalyst exhibited the highest efficiency for the photoreduction of CO2 with a high yield of 295 μmol-g−1 for CO under the experimental conditions. Also, hydrogen with low concentration was identified as a by-product under the experimental conditions. The photocatalyst had stability for six consecutive runs with negligible loss of the activity and no leaching of the cobalt content at the end of the sixth run of the photoreduction experiment. The stability of the photocatalysts is an advantage, which made it a suitable candidate for the current reaction system.

Covalently immobilized cobalt Phthalocyanine@MWCNT PDMS hollow fiber membrane for highly selective, reversible and bio-inspired oxygen transport

Facilitated oxygen transport is an effective strategy for the oxygen transport that may enhance the oxygen permeance and its selectivity, which may provide oxygen rich permeate that can be used in medical applications as in the present COVID-19 pandemic situation for providing the sufficient oxygen to the patients. This study presents the bio-inspired oxygen transport by covalently bonded Cobalt Phthalocyanine complex anchored on multi walled carbon nanotube (MWCNT) via axial ligand, incorporated in PDMS hollow fiber membranes with 0.05, 0.1, 0.5 and 1.0 wt % loadings. Successful functionalization of MWCNT was confirmed by Raman spectroscopy and X-ray photoelectron spectroscopy. The membranes were thoroughly characterized by using FE-SEM with elemental mapping, ATR-IR, DSC and TGA analysis. It demonstrated facilitated oxygen transport through the covalently immobilized Cobalt complex of the membrane with high oxygen permeance of 49 GPU as well as exceptional oxygen selectivity of 17 at 0.5 wt % Cobalt Phthalocyanine@ MWCNT loading. These values are highest among the known Cobalt complex based hollow fiber composite membranes in the literature suggesting its best utility in selective oxygen concentration for practical applications.

Photosensitive field effect transistor based on metallo-phthalocyanines containing (4-pentylphenyl) ethynyl moieties

The syntheses of new cobalt, manganese and zinc phthalocyanine complexes containing 4-pentylphenylethynyl substituents at the peripheral positions are reported. 4-[(4-pentylphenyl) ethynyl] phthalonitrile was obtained through Sonogashira coupling reaction. The new compounds have been characterized using UV–vis, FT- IR, 1H NMR, 13C NMR, and mass spectroscopy data. In order to study the dependence of device performance on the central metal atom, photosensitive field effect transistor based on tetra-substituted metallo phthalocyanines with [(4-pentylphenyl) ethynyl groups at peripheral positions were fabricated and characterized. Photoelectric characterization results showed that the device with active layer of 3 exhibits highest photoelectric performance with maximum field effect mobility (4.27 ×10-3 cm2/Vs), photosensitivity (72.05), and photo/dark current ratio (230). It was found that the photoelectric performance of the Pc compounds depends on the central metal atom which is found consistent with UV–vis spectrum. Surface topography of the sensing films were analyzed by atomic force microscopy.

Synthesis, antioxidant, DNA cleavage and antimicrobial properties of phthalocyanine complexes bearing the poly-hydroxyl groups

(4-((1-((2-(bis(2-hydroxypropyl) amino) ethyl) (2-hydroxypropyl) amino) propan-2-yl) oxy) phthalonitrile) (BHHP) was synthesized from reaction N, N, N′, N′- tetrakis (2-hydroxypropyl) ethylene diamine (SM) with 4-nitro phthalonitrile. Zinc, cobalt and copper phthalocyanine complexes were achieved from the reaction of BHHP compound with metal salts. Quantum chemical studies of these phthalocyanines have been computationally supported using density functional theory methods. The antioxidant properties of phthalocyanine compounds were determined with the help of l, l-diphenyl-2-picrilhydrazyl radical scavenging ability and chelating ability to iron ions. Compound 6 showed 72.8% inhibition of DPPH free radicals at 200 mg/L concentration and compound 4 showed 71.5% ferrous metal chelating activity at 200 mg/L concentration. The antimicrobial and DNA cleavage activities of compounds were also investigated. All tested phthalocyanine compounds showed excellent nuclease activity at all concentration. Antimicrobial activities of phthalocyanine compounds were detected using broth microdilution method and all test compounds demonstrated perfect antimicrobial activities. According to in vitro studies, copper phthalocyanine compound 6 has the best activity against the P. aeruginosa with 8 µg/mL of MIC value.

Characterization and preparation of green colored intramolecular novel ball type cobalt phthalocyanine complexes with single-chain polymer structure

The single-chain polymeric-ball type CoPcs (SCP-ball type CoPcs) were synthesized via the intramolecular macrocyclization reaction of cobalt phthalocyanines from poly(PNDEAMSt2%-co-St) (as named precursor copolymer1) and poly(PNDEAMSt6%-co-St), as named precursor copolymer2) as precursors under diluted solution conditions at 155 °C in presence of cyclohexanol. SCP-ball type CoPc1 and SCP-ball type CoPc2 were prepared from precursor copolymer1 and precursor copolymer2, respectively. The ball-type phthalocyanine moiety was incorporated into one side of the polymer chain. Both linear copolymer precursor and formation of ball-type cobalt phthalocyanine within a single-chain polymer were confirmed by FT-IR, 1H NMR, UV/Vis spectroscopy and MALDI-TOF-MS techniques. Particularly, the formation of SCP-ball type CoPc2 complex was characterized by almost disappearance of –CN band at 2230 cm−1 of the FT-IR and appearance of Q band between 601 and 673 nm. Average apparent activation energies of the thermal degradation of SCP-ball type CoPc2 calculated by three model-free methods in a period of α=0.07–0.90 have been estimated, and the activation energy for weight loss from 7% to 90% was increased from 33.16kj/mol to 36.73kj/mol, respectively. Optical and dielectrical measurements of linear copolymer precursor2 and SCP-ball type CoPc2 were carried out.

Synthesis, characterization, DFT study, conductivity and effects of humidity on CO2 sensing properties of the novel tetrakis-[2-(dibenzylamino)ethoxyl] substituted metallophthalocyanines

Novel tetrakis-[2-(dibenzylamino)ethoxyl] substituted nickel (II), cobalt (II) and manganese (II) phthalocyanines were synthesized by using 4-(2-(dibenzylamino)ethoxy)phthalonitrile with corresponding metal salts in 2-N, N-dimethylaminoethanol. New phthalonitrile ligand was prepared from 2-(dibenzylamino)ethan-1-ol and 4-nitrophthalonitrile in acetonitrile at reflux temperature using potassium carbonate as catalyst. The compounds was characterized by elemental analysis, infrared, ultraviolet–visible and matrix-assisted laser desorption/ionization time-of-flight mass spectroscopic methods. Density functional theory calculations were performed for structural and electronic properties. Direct current and alternating current conductivity properties of the metallophthalocyanine films were investigated between 293−523 K and frequencies 40−100 kHz. The direct current conductivity values were calculated as 5.29 × 10−10 S/cm, 2.39 × 10-9 S/cm, and 3.04 × 10−10 S/cm, for nickel, cobalt and manganese complexes (293 K) films, respectively. Activation energies of the films were 0.50-0.70 eV for T < 478 K. Alternating current conductivity results suggest that hopping model explains dominant charge transport mechanisms. Carbon dioxide sensing properties (1000–8000 ppm) of the metallophthalocyanine films were investigated at room temperature (293 K) in air as background. Additionally, effects of the relative humidity on carbon dioxide sensing properties were also investigated for relative humidity between 0–80 % RH in air. Response and response time values of the films were reported. Newly synthesized phthalocyanine complexes in this study were found to be reversible and sensitive to the carbon dioxide gas in humid air. Carbon dioxide sensing measurements revealed that sensitivity of the sensors increased with increasing carbon dioxide concentration and relative humidity. It is found that manganese phthalocyanine showed greater sensitivity than nickel- and cobalt phthalocyanine complexes.

Phthalocyanines including 2-mercaptobenzimidazole analogs: Synthesis, spectroscopic characteristics, quantum-chemical studies on the relationship between electronic and antioxidant properties

Abstract In this study, peripherally tetra 2-mercaptobenzimidazole group substituted cobalt and indium phthalocyanine complexes (2 and 3) were prepared from 4-(benzo[d]imidazole-2-ylthio)phthalonitrile (1) for the first time. Antioxidant behaviors and theoretical calculations of benzimidazole-substituted metallophthalocyanines are presented. The structures of these compounds were determined by the spectroscopic methods (IR, 1H NMR, UV–Vis and mass spectroscopies) and elemental analysis. Antioxidant activities of the compounds (1–3) were measured using 1,1-diphenyl-2-picrylhydrazyl (DPPH) method. Antioxidant activity was followed by 1 > 3 > 2 > Trolox. In addition, density functional theory (DFT) calculations were carried out to determine the stable electronic structure, charge density distributions, FMO energy eigenvalues, and electronegativity of the ligand (1) and complexes (2 and 3). NBO and QTAIM analysis were performed to investigate the relationship between the electronic properties and antioxidant activity of the compounds.