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Репрезентативные публикации за ноябрь 2018 г.

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Alexandra V.Smikhovskaia, Maxim S.Panov, Ilya I.Tumkin, Evgeniia M.Khairullina, Sergey S.Ermakov, Irina A.BalovaMikhail N.Ryazantsev, Vladimir A.Kochemirovsky In situ laser-induced codeposition of copper and different metals for fabrication of microcomposite sensor-active materials, Analytica Chimica Acta Volume 1044, 31 December 2018, Pages 138-146. DOI: 10.1016/j.aca.2018.07.042

Abstract

We report one-step in situ laser-induced synthesis of the conductive copper microstructures doped with iron, zinc, nickel, and cobalt with highly developed surface area. It was observed that the presence of chlorides of the aforementioned metals in the solutions used in our experiments increases the deposition rate and the amount of copper in the resulting deposits; it also leads to the deposit miniaturization. The laser deposition from solutions containing cobalt (II) chloride of concentration more than 0.003 M results in fabrication of copper microelectrode with better electrochemical properties than those deposited from solutions containing chlorides of other metals of the same concentration. Moreover, copper microelectrode doped with cobalt has demonstrated good reproducibility and long-run stability as well as sensitivity and selectivity towards determination of hydrogen peroxide(limit of detection-0.2 μM) and d-glucose (limit of detection-2.2 μM). Thus, in this article we have shown the opportunity to manufacture two-phase microcomposite materials with good electrical conductivity and electrochemical characteristics using in situ laser-induced metal deposition technique. These materials might be quite useful in development of new perspective sensors for non-enzymatic detection of such important analytes as hydrogen peroxide and glucose.


Anatoly A.Vereshchagin, Petr S.Vlasov, Alexander S.Konev, Galina A.Grechishnikova, Oleg V.Levin Novel highly conductive cathode material based on stable-radical organic framework and polymerized nickel complex for electrochemical energy storage devices, Electrochimica Acta, DOI: 10.1016/j.electacta.2018.11.149. DOI: 10.1016/j.electacta.2018.11.149

Abstract

Redox polymers bearing stable nitroxyl radical groups, such as poly-TEMPO-methacrylate (PTMA), are attractive candidates for application in power sources of novel kind, which combine the high power output of supercapacitors and high energy of rechargeable batteries. An important advantage of PTMA is the availability and low cost of the starting materials combined with high charging/discharging voltage, fast electron transfer kinetics and good mechanical properties of the polymer. However, low electron conductivity and high solubility in common organic electrolytes hamper the broad application of TEMPO-based compounds as cathode materials. In the present work, we report a simple strategy to overcome these limitations by the use of a practical and polymer-rich electrode based on redox-conducting polymer blends of polymerized nickel complexes with salen-type Schiff bases and PTMA. Electrochemical properties of the material are tested both in thin film systems and in asymmetric supercapacitor prototypes with aqueous electrolyte, which demonstrate high specific capacity (83 mAh g−1 at 1C, 53 mAh g−1 at 5C and 47 mAh g−1 at 10C), high rate capability as well as cycling stability (55% capacity retention after 1000 cycles).


Daniil A. Lukyanov, Alexander S. Konev, Konstantin Amsharov, Alexander F. Khlebnikov*, and Andreas Hirsch Diastereospecific and Highly Site-Selective Functionalization of C70Fullerene by a Reaction with Diethyl N-Arylaziridine-2,3-dicarboxylates, J. Org. Chem., 2018, 83 (22), pp 14146–14151. DOI: 10.1021/acs.joc.8b02240

Abstract

The diastereospecific and highly site-selective cycloaddition of N-arylazomethine ylides generated in situ from diethyl N-arylaziridine-2,3-dicarboxylates to C70 fullerene is reported. The reaction provides C70 fulleropyrrolidines in up to hundreds on a milligram scale as α- and β-adducts in a 4:1 ratio with a controlled stereochemical outcome: cis-aziridines give exclusively trans-adducts, and trans-aziridines give only cis-adducts. The 1H and 13C{1H} NMR spectra for different isomeric adducts were recorded and analyzed to identify some characteristic features, which permit an easy identification of isomeric adducts of this type.


Pavel A. Sakharov , Mikhail S. Novikov , and Alexander F. Khlebnikov* 2-Diazoacetyl-2H-azirines: Source of a Variety of 2H-Azirine Building Blocks with Orthogonal and Domino Reactivity, J. Org. Chem., V. 83, P. 8304−8314, 2018. DOI: 10.1021/acs.joc.8b01004

Abstract

A synthesis of 2-diazoacetyl-2H-azirines was developed starting from 2H-azirine-2-carbonyl chlorides, generated by Fe(II)-catalyzed isomerization of 5-chloroisoxazoles. 2-Diazoacetyl-2H-azirines easily undergo reactions characteristic of α-diazo ketones with preservation of the azirine ring. Reactions with hydrohalogenic, carboxylic, and p-toluenesulfonic acids provide novel 1-(3-aryl-2H-azirin-2-yl)-2-halo- and 2-(R-oxy)ethan-1-ones in good yields. The synthesized 2H-azirines can offer many possibilities for chemical manipulation in heterocyclic synthesis, due to the presence of highly reactive azirine and the exocyclic C(O)–CHN2 or C(O)–CH2X functionalities, which can show orthogonal or domino reactivity. The synthetic usefulness of the developed building blocks was demonstrated by the preparation of new types of heterocyclic dyads (azirine–oxazole, azirine–pyrazoline, azirine–thiazole, azirine–oxirane, pyrrole–oxazole) as well as an azirine chalcone analogue, 2-azidoacetyl-2H-azirine, and 2-diazoacetylaziridine derivatives.


Kirill I. Mikhailov , Ekaterina E. Galenko , Alexey V. Galenko , Mikhail S. Novikov , Alexander Yu. Ivanov, Galina L. Starova, and Alexander F. Khlebnikov* Fe(II)-Catalyzed Isomerization of 5-Chloroisoxazoles to 2H-Azirine-2-carbonyl Chlorides as a Key Stage in the Synthesis of Pyrazole–Nitrogen Heterocycle Dyads, J. Org. Chem., V. 83, P. 3177–3187, 2018. DOI: 10.1021/acs.joc.8b00069

Abstract

2-(1H-Pyrazol-1-ylcarbonyl)-2H-azirines were synthesized by in situ trapping of 2H-azirine-2-carbonyl chlorides, generated by Fe(II)-catalyzed isomerization of 5-chloroisoxazoles, with pyrazoles. According to DFT calculations, the selectivity of nucleophilic substitution at the carbonyl group of 2H-azirine-2-carbonyl chloride by a pyrazole nucleophile, which is a mixture of two tautomers, is controlled by thermodynamic factors. 2-(1H-Pyrazol-1-ylcarbonyl)-2H-azirines are excellent precursors for the preparation of two other pyrazole–nitrogen heterocycle dyads: 5-(1H-pyrazol-1-yl)oxazoles by photolysis and 1-(1H-pyrrol-2-ylcarbonyl)-1H-pyrazoles by a Ni(II)-catalyzed reaction with 1,3-dicarbonyl compounds. 5-(1H-Pyrazol-1-yl)oxazoles show strong emission in acetonitrile at 360–410 nm with high quantum yields.


Manfred Scheer, Oliver Hegen, Jens Braese, Alexey Timoshkin Bidentate Phosphanyl- and Arsanylboranes, Chem. Eur. J., 2018, early view. DOI: 10.1002/chem.201804772.

Abstract

A new class of neutral bidentate ligands with pnictogenyl-functional sites have been obtained. The reaction of tmeda∙(BH2I)2 (1, tmeda = tetramethylethylendiamine) with different phosphanides yields the corresponding bidentate phosphanylboranes tmeda∙(BH2PH2)2 (2a), tmeda∙(BH2PPh2)2 (2b) and tmeda∙(BH2tBuPH)2 (2c). This reaction strategy could be further extended to synthesize the first bidentate arsanylborane tmeda∙(BH2AsPh2)2 (3). Depending on the substituents on the phosphorus, these compounds form different Au(I) complexes, to build either polymeric tmeda∙(BH2PH2AuCl)2 (4a), or monomeric tmeda∙(BH2PPh2AuCl)2 (4b) products. These compounds form neutral oligomeric group 13/15 chain-like molecules by coordination to a boron moiety such as tmeda∙(BH2PH2BH3)2 (5a) and tmeda∙(BH2AsPh2BH3)2 (5b). DFT calculations provide insight into the differences between the syntheses of mono- and bidentate pnictogenylboranes.


Haschke S, Mader M, Schlicht S, Roberts AM, Angeles-Boza AM, Barth JAC, Bachmann J. Direct oxygen isotope effect identifies the rate-determining step of electrocatalytic OER at an oxidic surface, Nature Communicationsvolume 9, Article number: 4565 (2018). DOI: 10.1038/s41467-018-07031-1.

Abstract

Understanding the mechanism of water oxidation to dioxygen represents the bottleneck towards the design of efficient energy storage schemes based on water splitting. The investigation of kinetic isotope effects has long been established for mechanistic studies of various such reactions. However, so far natural isotope abundance determination of O2 produced at solid electrode surfaces has not been applied. Here, we demonstrate that such measurements are possible. Moreover, they are experimentally simple and sufficiently accurate to observe significant effects. Our measured kinetic isotope effects depend strongly on the electrode material and on the applied electrode potential. They suggest that in the case of iron oxide as the electrode material, the oxygen evolution reaction occurs via a rate-determining O-O bond formation via nucleophilic water attack on a ferryl unit.

Ответственный за содержание сайта Института химии: Роман Зумберов, r.zumberov@spbu.ru