- Cobalt phthalocyanine tetracarboxylic acid modified reduced graphene oxide: A sensitive matrix for the electrocatalytic detection of peroxynitrite and hydrogen peroxide
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The quantification of peroxynitrite (ONOO-, PON) and hydrogen peroxide (H2O2) is intrinsically difficult as both species show similar oxidative features located within a narrow potential. The sub-second lifetime of ONOO- at neutral pH further complicates the analysis. In this paper, we examine the electrocatalytic activity of cobalt phthalocyanine tetracarboxylic acid (CoPc-COOH) loaded reduced graphene oxide (rGO) films towards peroxynitrite and hydrogen peroxide detection. The rGO/CoPc-COOH matrix is synthesized by the reaction of graphene oxide (GO) and CoPc-COOH at 90 °C for 5 h under ultrasonication. The integration of CoPc-COOH and the reduction of GO to rGO was confirmed by X-ray photoelectron spectroscopy, FTIR, Raman, UV-vis spectroscopy and electrochemistry. The rGO/CoPc-COOH film showed high electrocatalytic activity and specificity for ONOO- at anodic potential with a sensitivity of ≈11.5 ± 1 nA nM-1 and a peroxynitrite detection limit of ≈1.7 nM. The rGO/CoPc-COOH films further exhibited electrocatalytic reduction of H2O2 with a sensitivity of 14.5 μA mM-1 and a detection limit of ≈60 μM for H2O2. This journal is
- Hosu, Ioana S.,Wang, Qian,Vasilescu, Alina,Peteu, Serban F.,Raditoiu, Valentin,Railian, Svetlana,Zaitsev, Vladimir,Turcheniuk, Kostiantyn,Wang,Li, Musen,Boukherroub, Rabah,Szunerits, Sabine
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- Aerobic oxidation of thioglycol catalysed by metallophthalocyanine in an organic-inorganic hybrid vesicle “cerasome”
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A molecular assembly of a hydrophobized metallophthalocyanine derivative embedded in a cerasome, an organic–inorganic hybrid vesicle with a lipid bilayer and silica surface, was a potent catalyst for aerobic oxidation of thioglycol. The catalytic activity was higher than those in hexadecyl 2-hydroxy-3-chloropropyl phosphate vesicles, sodium dodecylsulfate micelles, ethanol, and benzene.
- Hisaeda, Yoshio,Kikuchi, Jun-ichi,Sasaki, Yoshihiro,Song, Xi-Ming,Wu, Qiuhua,Yasuhara, Kazuma,Zhang, Dan,Zhang, Guolin,Zhang, Li
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- Method for preparing ketone or carboxylic acid through catalytic oxidation of secondary alcohol or primary alcohol
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The invention relates to a method for preparing ketone or carboxylic acid through catalytic oxidation of alcohol. The method specifically comprises the following steps: adding secondary alcohol or primary alcohol into a certain amount of organic solvent to serve as a raw material, forming an N-hydroxyphthalimide (NHPI)-phthalocyanine catalytic system and taking oxygen as an oxidant, and reacting for 9-36 hours at the reaction temperature of 60-120 DEG C under the condition of normal pressure to obtain the ketone or carboxylic acid with higher yield. Compared with the prior art, the method hasthe advantages of green and environment-friendly oxidant, cheap and easily-prepared catalyst, easiness in separation from the product, mild reaction conditions and the like, and is a green alcohol oxidation method.
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Paragraph 0030-0031
(2019/12/02)
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- Nanomolar detection of 4-aminophenol using amperometric sensor based on a novel phthalocyanine
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Novel cobalt (II) tetra-β-[N(2-(1,3-benzothiazole))carboxamide] phthalocyanine (CoTBTCAPc) has been synthesized for the first time. The dark green colored complex was characterized by different physicochemical and analytical techniques. Cyclic voltammetric studies revealed that the synthesized complex is redox-active nature. The CoTBTCAPc modified glassy carbon electrode (GCE/CoTBTCAPc) showed a stagnant charge transfer behavior for the redox probe whereas, composite hybrid of CoTBTCAPc with carbon nanoparticles (CNP) coated on GCE (GCE/CNP-CoTBTCAPc) showed facile and better charge transfer compared to the bare GCE. The GCE/CoTBTCAPc and GCE/CNP-CoTBTCAPc fabricated electrodes exhibited a decrease in over potential with the increase in oxidation peak current. Electrochemical oxidation of 4-aminophenol (4-AP) at nanomolar concentration was obtained in phosphate buffer pH 7.0 electrolytic media. The modified electrodes showed linear electrochemical response in the concentration range of 40–800 nM and the detection limit (LOD) was found as 13 and 11 nM (S/N = 3) for GCE/CoTBTCAPc and GCE/CNP-CoTBTCAPc electrodes respectively. Differential pulse voltammetric (DPV) technique showed linear response for the 4-AP oxidation in the concentration range of 100–1000 nM with sensitivity of 0.0328 and 0.4179 μA nM?1 cm?2 for the phthalocyanine and CNP-phthalocyanine modified electrodes respectively. In contrast, the amperometric sensor displayed linear response in the concentration range of 100–900 nM with sensitivity values of 0.4008 and 0.8887 μA nM?1 cm?2 and LOD of 40 and 30 nM for GCE/CoTBTCAPc and GCE/CNP-CoTBTCAPc electrodes respectively. The GCE/CNP-CoTBTCAPc showed selectivity for 4-AP even in the presence of interfering organic and inorganic species. This stable and simple sensor offers an opportunity for the electrochemical sensing of 4-aminophenol in real sample analysis like 4-AP in paracetamol tablets.
- Nemakal, Manjunatha,Aralekallu, Shambhulinga,Mohammed, Imadadulla,Pari, Malathesh,Venugopala Reddy,Sannegowda, Lokesh Koodlur
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p. 342 - 353
(2019/06/25)
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- Improved Synthesis of Soluble Metal-Free/Metal Phthalocyanine Tetracarboxylic Acids and Their Application in the Catalytic Epoxidation of Cyclohexene
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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. Graphical Abstract: 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. [Figure not available: see fulltext.]
- Sun, Xiaoling,Wang, Li,Tan, Zhi
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p. 1094 - 1102
(2015/08/04)
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- Highly efficient, mild, bromide-free and acetic acid-free dioxygen oxidation of p-nitrotoluene to p-nitrobenzoic acid with metal phthalocyanine catalysts
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Four metal tetracarboxyl phthalocyanines were synthesized and characterized by elemental analysis and mass spectrometry. p-Nitrobenzoic acid was efficiently prepared in high yield from bromide-free and acetic acid-free aerobic oxidation of p-nitrotoluene using metal phthalocyanines as catalysts under mild conditions in alkali-methanol solution. Up to 88.8% isolated yield of p-nitrobenzoic acid was obtained with the catalysis of tetracarboxyl phthalocyanine cobalt (0.13 mol %, based on the moles of p-nitrotoluene) optionally combined with a small amount of dimethylformamide in the presence of 2.0 MPa dioxygen at 30-60°C. The effect on catalytic performance of a carboxyl group introduced into the phthalocyanine ring was further discussed on the basis of metal coordination chemistry theory.
- Song, Xufeng,She, Yuanbin,Ji, Hongbing,Zhang, Yanhui
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p. 297 - 301
(2012/12/24)
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- Phthalocyanines and related compounds: XXXVII. Synthesis of covalent conjugates of carboxy-substituted phthalocyanines with α-amino acids
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Methods of synthesis of covalent conjugates of metal complexes of octa-4,5-carboxy- and tetra-4-carboxyphthalocyanine, as well as of octa-6,7-carboxy-2,3-naphthalocyanine with α-amino acids, glycine and sarcosine, were developed and certain properties of
- Mikhalenko,Solov'eva,Luk'yanets
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p. 451 - 459
(2007/10/03)
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- Cyclic Voltammograms of Thin Film Cobalt Phthalocyanine Derivatives, Assignment of Each Cathodic Wave Formation of Protonated Species of Cobalt(I) Phthalocyanines
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Cyclic voltammograms(cvs) of thin films of (29H,31H-phthalocyaninato-N29,N30,N31,N32)cobalt(II): CoPc (1), CoPc(COOH)4 (2), and monomeric CoPc(COOH)8 (3) shown in Fig. 1 have been investigated.Cv of 2 on a glassy carbon electrode, in a N2 saturated 1 M sulfuric acid solution, shows four cathodic waves at 0.10 V (a), -0.20 V (b), -0.48 V (c), -0.73 V (d) vs. sce.Each wave is assigned as follows; both a and b: redox of central Co(II)/α-form of HCo(I)Pc(COOH)4 (4), c: redox of 4/H2Co(I)Pc(COOH)4 (6), d: formation of H3Co(I)Pc(COOH)4 (7).Incomplete air oxidation of 7 gives a film β-form of HCoPc(COOH)4 (5) which showed a cathodic wave at -0.56 V vs. sce (d) to give 7.Chemical reduction of 2 with Na2S was followed by cv of thin film of the reaction mixture.Protonation of the product gives semistable film of 5.These assignments are based on the visible spectra, color change and cv behavior of the thin films of 2 under polarization at various potentials.Cv of 3 shows four reversible cathodic waves corresponding to that of 2.Reversibility of the forth wave (e) seemed to relate strongly with the character and the number of the substituent on the macrocyclic ring. - Key words: Electrical Properties / Electrochemistry
- Kusuda, Kusuke,Shiraki, Kaneto,Yamaguchi, Hidemasa
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p. 725 - 730
(2007/10/02)
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