Phthalocyanine Tetracarboxylic Acid Research Articles

Cobalt phthalocyanine conjugated SBA-15 mesoporous silica via the Ugi four-component reaction: A potential heterogeneous catalytic nanocomposite for CO2 fixation reaction

Owing to the porosity, high hydrothermal and mechanical stability of SBA-15, this type of silica mesoporous has attracted significant attention from many researchers for catalytic systems design. Accordingly, SBA-15 was utilized in this work as eco-friendly support to synthesize an effective heterogeneous catalytic nanocomposite based on the conjugation or immobilization of metalophthalocyanines (MPcs). For this purpose, initially, SBA-15 was modified by (3-aminopropyl)triethoxysilane (APTES) as an amination agent to produce SBA-15-NH2 and then participated in a straightforward one-pot Ugi four-component reaction (Ugi-4CR) of cyclohexyl isocyanide, benzaldehyde, and cobalt (II) phthalocyanine tetracarboxylic acid (Co-PcTCA) as an acid component. Afterward, the catalytic activity of the cobalt (II) phthalocyanine immobilized via SBA-15-NH2 (Co-PcTCA/SBA-15-N) was examined in the CO2 fixation reaction for the preparation of cyclic carbonates in water as a green solvent. Interestingly, catalytic experiments revealed that SBA-15 as a porose support could considerably ameliorate the catalytical properties of the Co-PcTCA regarding the CO2 fixation reaction via high CO2 adsorbent capacity in the shortest reaction time.

Amines functionalities on chitosan boasting photocatalytic activity of cobalt(II)-phthalocyanine in water-splitting

Water as an abundant and safe source has been employed for the hydrogen generation to cutback use of toxic fossil fuels. Promotion of this reaction by photocatalytic approaches is worthy solution to stay away from expenditure of complicated electrochemical pathways. Amongst photocatalysts, noble metal-based catalysts are widely utilized in this reaction suffering from high-cost. Herein, cobalt(II)-phthalocyanine tetra-carboxylic acid was bonded to chitosan by amidation reaction to afford a new composite with enhanced both semiconductor behavior and catalyst activity. This photocatalyst efficently harvest light in a broad region of UV-Vis to generate electron/hole pairs to promote water-splitting with the TOF of 510 h−1 at ambient conditions without any additive. Chitosan as a support of the catalyst facilitated the catalyst separation, improved optical action, and assisted to the hydrogen evolution by forming ammonioum intermediates. This novel composite could be considered as an efficent photocatalyst with low-cost and easy handling.

Recent Strategies for Using Monolithic Materials in Glycoprotein and Glycopeptide Analysis

There is continuous effort towards developing monolithic materials as solid supports for the separation, enrichment, and digestion of glycoproteins. The intention of this review is to discuss and summarize work reported in this area during the period 2015–2021 as a follow-up to our prior review. Reports from the past three decades have already proven the advantages of monolithic materials, such as the ease with which they can be prepared and functionalized, their high permeability and low resistance to mass transfer, and their stability over a wide range of pH. Recent works on glycoprotein analysis introduce different strategies in using monolithic materials specifically in separation, enrichment, and identification of glycoproteins, glycopeptides, and free glycans. A majority of these are focused on boronic acid affinity-based technique and others on lectin affinity and HILIC-based techniques. There are also newly developed ligands that utilize different interactions with glycans, such as encapsulation into β-cyclodextrin vesicles, CH- or OH-π interactions with fullerenes, immunoaffinity with monoclonal antibodies, H-bonding interactions with metallophthalocyanines, coordination interactions with cobalt phthalocyanine tetracarboxylic acid, and hydrophilic interaction with cyclodextrin molecular tubes, zwitterionic iminodiacetic acid, and boric acid. Recent strategies for developing on-line, multidimensional systems use immobilized monolithic enzyme reactors (IMERs) for high-throughput glycoprotein analysis. These works serve as contributions to better understand glycan structure-function relationship, as glycoproteins are now widely accepted disease biomarkers.

Detection of Kallikrein-Related Peptidase 4 with a Label-free Electrochemical Impedance Biosensor Based on a Zinc(II) Phthalocyanine Tetracarboxylic Acid-Functionalized Disposable Indium Tin Oxide Electrode.

A new impedimetric biosensing system based on kallikrein-related peptidase 4 (KLK 4) antigen-specific antibodies and a zinc(II) phthalocyanine tetracarboxylic acid (Zn-PcTCa) matrix material was developed for the first time in this study. First, a Zn-PcTCa-coated indium tin oxide surface was used as an interface matrix material for the immobilization of anti-KLK 4 antibodies, and they bound to the platform via amide bonds. In the presence of KLK 4 antigens, the anti-KLK 4 antibodies specifically captured these antigens and caused changes in the electrochemical properties of the system. Randles equivalent circuit was utilized to evaluate the impedimetric signal, which was measured with the help of an electrochemical impedance spectroscopy method. After the specific interaction, the electron transfer resistance (Rct) was remarkably increased and displayed a linear relationship with the level of the KLK 4 antigen in the range of 0.02-15 pg/mL, with a a detection limit of 6.8 fg/mL. The designed biosensor was able to detect a KLK 4 antigen with good sensitivity, excellent specificity, and high stability. In addition, because of having a low-cost and robust procedure for fabrication, it could be repeatedly used in several areas including clinical diagnosis.

Highly improved photoreduction of carbon dioxide to methanol using cobalt phthalocyanine grafted to graphitic carbon nitride as photocatalyst under visible light irradiation

A substantially improved methanol yield was achieved from the photoreduction of carbon dioxide under visible light by using a hybrid photocatalyst consisting of molecular cobalt phthalocyanine tetracarboxylic acid (CoPc-COOH) complex immobilized to the organic semiconductor graphitic carbon nitride (g-C3N4) and triethylamine as sacrificial electron donor. The structural and morphological features of the hybrid photocatalyst determined by various techniques like FTIR, UV–Vis, Raman, XPS, TGA, BET etc. After 24 h of light irradiation, the methanol yield by using g-C3N4/CoPc-COOH photocatalyst (50 mg) was found to be 646.5 µmol g−1cat or 12.9 mmol g−1cat with conversion rate 538.75 µmol h−1 g−1cat. However, the use of homogeneous CoPc-COOH (6.5 µmol Co, equivalent to g-C3N4/CoPc-COOH) and g-C3N4 (50 mg) provided 88.5 μmol (1770 μmol g−1cat) and 59.2 μmol (1184 μmol g−1cat) yield of methanol, respectively under identical conditions. The improved photocatalytic efficiency of the hybrid was attributed to the binding ability of CoPc-COOH to CO2 that provided the higher CO2 concentration on the support. Further, the semiconductor support provided better electron mobility and charge separation with the integrated benefit of facile recovery and recycling of the material at the end of the reduction process.

Coordination Nanosheets of Phthalocyanine as Multifunctional Platform for Imaging-Guided Synergistic Therapy of Cancer.

"All-in-one" nanodrugs integrating various functionalities into one nanosystem are highly desired for cancer treatment. Coordination nanosheets as one type of two dimensional (2D) nanomaterials offer great opportunities, but there is lack of enough candidates. Here, a new kind of coordination nanosheets based on phthalocyanine are constructed. Manganese phthalocyanine (MnPc) tetracarboxylic acid is employed as photoactive ligand to form MnPc nanosheets; meanwhile, hyaluronic acid (HA) is coated on their surface. The obtained MnPc@HA nanosheets exhibit superior near-infrared (NIR) photothermal effect with photothermal conversion efficiency of 72.3%, much higher than those of the previously reported photothermal agents. Due to their 2D nanostructures, MnPc@HA nanosheets possess superhigh drug-loading capacity for chemotherapy drug curcumin. With HA as a targeting group, the nanosheets selectively accumulated in CD44 overexpressed tumors, followed by drug release under the control of NIR light. Moreover, MnPc@HA nanosheets with intrinsic paramagnetism can serve as T1 contrast agent for magnetic resonance imaging. The synergistic effect of phototherapy and chemotherapy endows curcumin-loaded MnPc@HA nanosheets with superior tumor-eradicating efficacy. Besides, MnPc@HA nanosheets are biocompatible and safe for biomedical applications. This work provides novel insight for developing new multifunctional platforms based on 2D coordination nanosheets to synergistically combat cancer.

Cobalt Phthalocyanine Tetracarboxylic Acid Functionalized Polymer Monolith for Selective Enrichment of Glycopeptides and Glycans.

In this study, poly(glycidyl methacrylate-ethyleneglycol dimethacrylate) monolith functionalized with cobalt phthalocyanine tetracarboxylic acid is prepared. The polymer monolithic material is used for glycopeptides enrichment coupled with MALDI-TOF MS. By taking advantage of cobalt phthalocyanine including hydrogen bonds between isoindole subunits of phthalocyanine and glycans, coordination interaction between cobalt and glycopeptides, the monolithic material is successfully applied to the enrichment of glycopeptides efficiently and selectively. With IgG and horse radish peroxidase as the model glycoproteins, 28 and 17 glycopeptides could be identified respectively after enrichment with the monolith, only four and three glycopeptides could be obtained for direct analysis. The monolith is also employed to the digests mixture of BSA and IgG (50:1, m/m), indicating the high enrichment selectivity of glycopeptides even in the presence of a large interference ratio. The detection limit is determined to be 6.7fmol, implying that the present method had great potential for trace sample analysis. In addition, the monolith was successfully applied to the enrichment of N-linked glycans in human serum samples, demonstrating its great potential for the analysis of glycoproteins.

Preparation of cobalt phthalocyanine functionalized polymer monolith and application to enrichment of transferrin glycopeptides

Poly(glycidyl methacrylate-ethyleneglycol dimethacrylate) (Poly(GMA-EDMA)) monolith functionalized with cobalt phthalocyanine tetracarboxylic acid (CoPcTc) was prepared. The monolith was used for transferrin (Tf) glycopeptide enrichment. By taking advantage of hydrogen bonds between isoindole subunits of phthalocyanine and glycans and coordination interaction between cobalt and glycopeptides, the monolithic material was efficient and selective. After enrichment of transferrin through the functionalized monolith, 17 glycopeptides were identified by electrospray ionization quadrupole time-of-flight mass spectrometry. When the concentration of transferrin was reduced to 8.8×10-10mol/L, three glycopeptides could still be obtained. The present method has great potential for trace sample analysis.

Improved Synthesis of Soluble Metal-Free/Metal Phthalocyanine Tetracarboxylic Acids and Their Application in the Catalytic Epoxidation of Cyclohexene

Soluble metal-free and metal (copper (II), iron (III), and cobalt (II)) phthalocyanine tetracarboxylic acids (5–8) were synthesized using a novel method consisting of improved hydrolysis based on the diazo reaction. The obtained compounds (5–8) were characterized by X-ray diffraction, UV–Vis spectrometry, and FT-IR spectrometry and then utilized as catalysts for the epoxidation of cyclohexene with molecular oxygen as oxidant. Reaction conditions including reaction time, temperature, catalyst amount, and isobutyraldehyde/cyclohexene ratio were optimized to achieve the highest selectivity of cyclohexene oxide. Metal-free phthalocyanine tetracarboxylic acid (5) and metal (copper (II), iron (III), and cobalt (II)) phthalocyanine tetracarboxylic acids (6–8, respectively) were compared. Complexes 6–8 exhibited higher catalytic activity than compound 5 under the optimal conditions. Four soluble metal-free and metal PTCs were synthesized using a novel method, and were utilized as catalysts for the epoxidation of cyclohexene with molecular oxygen as the oxidant. A total of 58.1% selectivity and yield of cyclohexene oxide were achieved under the optimal condition.

Cobalt phthalocyanine tetracarboxylic acid modified reduced graphene oxide: a sensitive matrix for the electrocatalytic detection of peroxynitrite and hydrogen peroxide

The electrocatalytic properties of cobalt phthalocyanine modified reduced graphene oxide for peroxynitrite and hydrogen peroxide are investigated.

Epoxidation of Olefins Catalyzed by Metal Phthalocyanine Tetracarboxylic Acid

Four metal phthalocyanine tetraboxylic acid complexes(M-PTC) were synthesized and characterized by the IR,UV spectrometry and XRD.The catalytic activities of these complexes were screened using the epoxidation of olefins with molecular oxygen as oxidant.The factors including the category and amount of solvents,reaction temperature,as well as the amounts of isobutyradehyde(IBA) and catalyst were evaluated.It was found that Fe-PTC was the best catalyst.Under optimized conditions(ClCH2 CH2 Cl as the solvent,n(cyclooctene) ∶ n(catalyst) ∶ n(IBA) = 4∶ 0.002 5∶ 16,45 ℃,5 h),the epoxidation of cyclooctene can give 91.1% yield,91.1% selectivity and 1 457 turn over number(TON).Fe-PTC could be reused for 7 times without loss of catalytic activity.The IR spectra of the fresh-prepared and recovered catalysts indicated that the structure of the catalyst remained unchanged before and after reaction.

Planar polyphthalocyanine cobalt absorbed on carbon black as stable electrocatalysts for direct methanol fuel cell

In this work, a novel catalyst is prepared by dispersing planar polyphthalocyanine cobalt (PPcCo) synthesized by polymerizing cobalt (II)-4, 4′,4″,4‴-phthalocyanine tetracarboxylic acid (TcPcCo) using a high surface area carbon powder (Vulcan XC 72), and then heat-treated in argon (Ar) atmosphere. The polymer and PPcCo/C catalysts are characterized systematically by a variety of methods, such as ultraviolet–visible (UV–vis) spectrophotometer, Fourier transform infrared spectrometer (FT-IR), thermogravimetric analysis (TGA), X-ray powder diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and transmission electron microscope (TEM). Results show that the PPcCo obtained is stable below 600 °C. The active site of PPcCo/C is CoN 4 in phthalocyanine ring, and the PPcCo is dispersed homogeneously on the surface of XC 72. Electrocatalytic properties and electrochemical stability of the catalysts in 0.5 mol L −1 H 2SO 4 are evaluated by RDE measurements. The initial potential for O 2 reduction in O 2-saturated H 2SO 4 is 0.81 V and it catalyzed O 2 reduction mainly through a four-electron process. Almost no performance degradation is observed over continuous cyclic voltammetry (CV) at 10,000 cycles (4 days). Polarization curves obtained by linear sweep voltammetry (LSV) at 200 cycles also show no change. PPcCo/C catalysts display significant electrocatalytic performance for O 2 reduction, tolerance towards methanol, and long-term stability.

Modification of sensing properties of metallophthalocyanine by an ECR plasma

Lead Phthalocyanine (PC) tetracarboxylic acid prepared by chemical reaction from phthalic anhydride and urea was used as sensor element for sensing humidity and alcohol vapors. The surface was treated with electron cyclotron resonance (ECR) plasma consisting of 25% H 2 and 75% N 2. Remarkable improvement in the selectivity with respect to ethyl alcohol and reduction in the sensitivity for humidity was observed after this treatment. The response and recovery time for resistive sensing were of the order of 50 and 30 s respectively. X-ray photoelectron spectroscopy and Fourier transformation infra red studies showed that the increased cross-linking of PC is responsible for the creation of new functional groups which have imparted the sensing of alcohol vapor through extrinsic doping.

Electrochemical reduction of substituted cobalt phthalocyanines adsorbed on graphite

Unsubstituted phthalocyaninatocobalt(II) [PcCo] and the cobalt complexes of the substituted ligands octabutoxyphthalocyanine [Pc(OBu) 8Co], octacyanophthalocyanine [Pc(CN) 8Co], phthalocyaninetetracarboxylic acid [Pc(COOH) 4Co] and tetrapyridotetraazaporphyrin [TPyTAPCo] were absorbed on the basal plane of pyrolytic graphite (BPG) from solutions in organic solvents to form ultrathin films. The films were studied by cyclic voltammetry in the presence of an inert aqueous electrolyte to yield the redox characteristics of the films. The films undergo reduction and reoxidation at the ligand inner π system as well as at the metal centre with a linear dependence of peak currents on scan rate that is typical for surface-confined species. The kinetics of the two reactions are further discussed on the basis of the analysis of peak shapes and charge found in the different waves in the cyclic voltammograms. The redox potentials of both reactions are shifted according to the electron donating or withdrawing character of the ligand's periphery as seen by comparison to molecular orbital (MO) calculations and ultraviolet photoelectron spectroscopy (UPS) results. During the reduction step, protons from the electrolyte are interacting with the films and are desorbed during reoxidation, leading to a strong pH dependence of the redox potential. The acid—base properties of the ligands determine a threshold pH above which the potential of the metal-centred first reduction is no longer dependent on pH. The ligand-centred second reduction, however, led to interaction with protons over the whole accessible pH range. Both electrode reactions are discussed in view of chemical interactions of the protons with the various ligand systems.

Role of polycation promoters in the cobalt(II) phthalocyaninetetracarboxylic and ‐octacarboxylic acid‐catalyzed autoxidation of mercaptoethanol

AbstractThe promoting effects of 2,4‐ionene on the cobalt(II) phthalocyaninetetracarboxylic acid‐[CoPc(COOH)4] and cobalt(II) phthalocyanineoctacarboxylic acid‐[CoPc(COOH)8] cata‐lyzed autoxidation of 2‐mercaptoethanol were studied. Dimerization of the CoPc(COOH)4 catalyst, combined with the disappearance of the catalytically inactive μ‐peroxo complex and the appearance of substrate enrichment in the presence of 2,4‐ionene, results in a 40‐fold enhancement of the oxidation rate as compared with the polymer‐free system. UV‐VIS spectroscopy indicates that CoPc(COOH)8 is incapable of forming μ‐peroxo complexes or 2,4‐ionene‐induced dimeric catalyst species under normal reaction conditions. Thus, it was possible to study exclusively the ionene‐induced effect of substrate enrichment. Addition of 2,4‐ionene to an aqueous CoPc(COOH)8 solution results in an activity enhancement by a factor of 2‐3, which can be ascribed to substrate enrichment. Additionally, using mono‐disperse ionene oligomers showed a molecular weight dependence of 2,4‐ionene on the catalytic activity of CoPc(COOH)8, as was observed for the conventional 2,4‐ionene/cobalt phthalocyaninetetrasodiumsulfonate system. The optimal polycation/catalyst ratios of both systems decrease with increasing chain length of 2,4‐ionene, until a constant value is reached. This leads to the conclusion that the optimal polymer/catalyst ratios are predominantly determined by substrate enrichment. © 1995 John Wiley & Sons, Inc.

Characterization of poly-L-lysine adsorption onto alkanethiol-modified gold surfaces with polarization-modulation Fourier transform infrared spectroscopy and surface plasmon resonance measurements

The electrostatic adsorption of poly-L-lysine molecules onto a vapor-deposited gold film modified with a carboxylic acid-terminated alkanethiol monolayer is monitored with the spectroscopic techniques of polarization-modulation Fourier transform infrared (PM-FTIR) spectroscopy and surface plasmon resonance (SPR). The PM-ITIR spectrum of a monolayer of poly-L-lysine (PL) adsorbed onto a self-assembled monolayer of 11-mercaptoundecanoic acid (MUA) indicates that the lysine residues and the MUA carboxylic acid moieties form ammonium-carboxylate ion pairs which electrostatically bind the polypeptide to the surface. The PL molecules can be desorbed from the surface by rinsing with a buffer solution at a pH that destroys the ion pairing (pH 12). Measurements of the shift in the SPR angle upon adsorption were used to determine the thicknesses of the adsorbed monolayers; the MUA and PL monolayers were found to be 17.0 and 10.5 A thick, respectively. These thickness results suggest that the poly-L-lysine monolayer adsorbs onto the packed MUA surface in an extended conformation with the PL backbone lying parallel to the surface. Subsequent exposure ofthe PL monolayer to a solution ofiron phthalocyanine tetracarboxylic acid (FePc) resulted in the adsorption of a third layer onto the surface. The ability of the adsorbed PL molecules to interact with FePc indicates the presence of free lysine residues available for interaction with molecules other than the MUA monolayer.

A rapid safranin-metal phthalocyanine double staining technique for plants.

Pure metal 4,4',4'',4'''-tetra-substituted, sulfo-, carboxy- and nitrophthalocyanines were synthesized. Mounted, deparaffinized and partially dehydrated sections of plant tissues were stained with 0.5% safranin in 50% alcohol for 5-10 min. Excess safranin was removed with a series of 70%, 95% and absolute alcohol washes. The sections were then stained for 2-3 min using metal 4,4',4'',4'''-phthalocyanine tetracarboxylic acid (MPTC, 0.5% (V/V) containing a few drops of dilute sodium hydroxide), metal 4,4',4'',4'''-tetrasulfophthalocyanine (MPTS, 0.5% (V/V)) or metal tetranitrophthalocyanine (MPTN, 0.5% (V/V) in dimethyl sulfoxide). The sections were washed with 95%, then absolute alcohol; however, the metal tetranitrophthalocyanine section was washed only with absolute alcohol. Stained sections were treated briefly with xylene, then mounted on a coverslip. Bright peacock blue (MPTC and MPTS using Cu, Co or Ni), turquoise blue (MPTN using Cu or Ni) or parrot green (zinc phthalocyanine tetracarboxylic acid-ZnPTC, zinc phthalocyanine tetranitro derivative-ZnPTN) colors were obtained. Lignin-containing cells were stained red by safranin and the remaining cell structures were stained by the metal phthalocyanine complex with color brightness superior to that of fast green. Uniform staining, no color fading after a year, reliability, brief staining times, high color contrast (log epsilon = 4.0-4.9) and ease of use make this double staining combination ideal for routine use and photomicrography.

Enhanced catalytic activity of metal salts of metal phthalocyanine tetracarboxylic acids in the autoxidation of thiophenol in hexane

Catalytic activities of metal (Fe3+, Co2+, Ni2+ and Cu2+ salts of metal (FeCl2+, Co2+, Ni2+ and Cu2+)) phthalocyanine tetracarboxylic acids dispersed on a carrier in the autoxidation of thiophenol have been investigated. Absorptions of O2 in the presence of the catalysts were measured. P values (percentages of the absorbed O2 after 30 min. per theoretical volume) and T values (absorbed O2 mol s−1 (cat. mol)−1/substrate mol l−1) at the original point were adopted to evaluate the catalytic activities. Fe3+ salt of cobalt phthalocyanine tetracarboxylic acid showed the highest activity. The mechanism of the activity was investigated electrochemically by using carbon paste electrodes containing the catalyst.

Phthalocyanine polymers. III. Poly(nickel phthalocyanine)benzimidazole as a novel high‐temperature‐resistant polymer

A new type of poly(nickel phthalocyanine)benzimidazole was prepared by the condensation reaction between nickel (11) 4,4′,4″,4″′-phthalocyanine tetracarboxylic acid dihydrate and 3, 3′-diaminobenzidine. The reaction was investigated by both the melt and solution condensation methods. This polymer showed good thermal and thermo-oxidative stability. Also noteworthy is its high thermal stability with a char yield of 88% at 800°C in nitrogen. No catastrophic decomposition was observed up to 1100°C. A qualitative study of decomposition in both air and nitrogen is presented. Elemental analyses agreed well with the proposed structure. Infrared (IR) and thermogravimetric analysis (TGA) studies were performed to characterize this polymer, and isothermal gravimetric analysis was done to determine its long-term thermal stability. The apparent activation energies for the thermal degradation in air and nitrogen are given.

Phthalocyanine polymers. III. Poly(nickel phthalocyanine)benzimidazole as a novel high‐temperature‐resistant polymer

AbstractA new type of poly(nickel phthalocyanine)benzimidazole was prepared by the condensation reaction between nickel (11) 4,4′,4″,4″′‐phthalocyanine tetracarboxylic acid dihydrate and 3, 3′‐diaminobenzidine. The reaction was investigated by both the melt and solution condensation methods. This polymer showed good thermal and thermo‐oxidative stability. Also noteworthy is its high thermal stability with a char yield of 88% at 800°C in nitrogen. No catastrophic decomposition was observed up to 1100°C. A qualitative study of decomposition in both air and nitrogen is presented. Elemental analyses agreed well with the proposed structure. Infrared (IR) and thermogravimetric analysis (TGA) studies were performed to characterize this polymer, and isothermal gravimetric analysis was done to determine its long‐term thermal stability. The apparent activation energies for the thermal degradation in air and nitrogen are given.