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High-temperature polymer-electrolyte membrane fuel cells (HT-PEMFCs) are a very important type of fuel cells since they operate at 150–200 °C, making it possible to use hydrogen contaminated with CO. However, the need to improve the stability and other properties of gas-diffusion electrodes still impedes their distribution. Self-supporting anodes based on carbon nanofibers (CNF) are prepared using the electrospinning method from a polyacrylonitrile solution containing zirconium salt, followed by pyrolysis. After the deposition of Pt nanoparticles on the CNF surface, the composite anodes are obtained. A new self-phosphorylating polybenzimidazole of the 6F family is applied to the Pt/CNF surface to improve the triple-phase boundary, gas transport, and proton conductivity of the anode. This polymer coating ensures a continuous interface between the anode and proton-conducting membrane. The polymer is investigated using CO2 adsorption, TGA, DTA, FTIR, GPC, and gas permeability measurements. The anodes are studied using SEM, HAADF STEM, and CV. The operation of the membrane–electrode assembly in the H2/air HT-PEMFC shows that the application of the new PBI of the 6F family with good gas permeability as a coating for the CNF anodes results in an enhancement of HT-PEMFC performance, reaching 500 mW/cm2 at 1.3 A/cm2 (at 180 °C), compared with the previously studied PBI-O-PhT-P polymer. [ABSTRACT FROM AUTHOR]

[Display omitted] Using a diastereomeric mixture of (S)-methionine S -oxide as an example, kinetic preference of methionine-γ-lyase toward a stereogenic center at the γ-sulfur atom of the (2 S , R S) diastereomer was discovered for the first time. [ABSTRACT FROM AUTHOR]

Enantioselective synthesis of thiazole‐containing α‐perfluoroalkylated cyclic amines was elaborated. Organocatalytic Strecker reaction with 5–7 membered cyclic ketimines was used as a key step of sequence. The prepared chiral amino nitriles bearing CF3‐ or C2F5‐group in the alpha position were transformed into the corresponding chiral thioamides by the reaction with hydrogen sulfide. Subsequent reaction with alpha bromo‐ or chloro‐substituted carbonyls allowed obtaining perfluoroalkylated analogues of natural thiazole‐containing cyclic amines in high isolated yield and up to > 99 % ee. Enantioselective synthesis of thiazole‐containing α‐perfluoroalkylated cyclic amines was elaborated. Enantioselective Strecker hydrocyanation followed by the reaction with hydrogen sulfide resulted in highly efficient formation of the corresponding thioamides. Finally, Hantzsch reactions provided access to a family of fluorinated analogues of natural products. [ABSTRACT FROM AUTHOR]

[Display omitted] A novel catalyst based on Pd nanoparticles encapsulated in a chiral crystalline organic salt matrix is prepared from tetrasodium tetrakis(4-sulfonatophenyl)methane and tetrakis[4-(S)-prolinamidophenyl]methane in water at room temperature under hydrogen atmosphere. The hydrogenation of p -nitrobenzaldehyde over this catalyst stalls at the stage of p -aminobenzyl alcohol, whereas Pd/C brings the reduction further to p -toluidine. [ABSTRACT FROM AUTHOR]

Highlights on the development of ferrocene biochemistry in Russia since the 1950s are given. Here, avoiding high‐toxic precursors, ferrocene‐based imidazoles and benzimidazoles (16 compounds) were synthesized in good to high yields via the reaction of the α‐(hydroxy)alkyl ferrocenes with modified heterocycles using oxalyl chloride to activate imidazole system. Mild conditions (room temperature, chloroform, stirring for up to 1.5 h) allowed preparing a number of various ferrocene‐containing imidazoles, which are promising as antitumor agents. The analytical HPLC method was successfully applied to enantioseparation of the resulting ferrocene enantiomers (Chiralcel OD column). Antitumor activities of the preparing compounds against murine solid tumours such as Acatol adenocarcinoma and Ca755 carcinoma have been studied in vivo. Some of the tested compounds have been strong effective against Acatol adenocarcinoma. The value of the tumour growth inhibition coefficient was about 90% versus control in this strain. [ABSTRACT FROM AUTHOR]

Composite materials have been used based on coordination polymers or microporous metal-organic frameworks (MOFs) combined with mesoporous matrices for adsorption-related techniques, which enable outflanking some adverse phenomena manifested during pristine components operation and enhance the performance and selectivity of the resulting materials. In this work, for the first time, the novel HKUST-1@BPS composites synthesized by the microwave-assisted (MW) technique starting from microporous HKUST-1 (Cu3(btc)2) MOF and biporous silica matrix (BPS) with bimodal mesopore size distribution were comparatively studied as materials for liquid-phase adsorption techniques utilizing the high-performance liquid chromatography (HPLC) method and benzene as a model adsorbate. It was established that the studied HKUST-1@BPS composites can function as stationary phases for HPLC, unlike the pristine HKUST-1 and bare BPS materials, due to the synergetic effect of both components based on the preliminary enhanced adsorbate mass transfer throughout the silica mesopores and, subsequently, its penetrating into HKUST-1 micropores. The suggested mechanism involves the initial deactivation of open metal Cu2+ sites in the HKUST-1 framework structure by isopropanol molecules upon adding this polar component into the mobile phase in the region of the isopropanol concentration of 0.0 to 0.2 vol.%. Thereafter, at the medium range of varying the isopropanol concentration in the eluent of 0.2 to 0.3 vol.%, there is an expansion of the previously inaccessible adsorption centers in the HKUST-1@BPS composites. Subsequently, while further increasing the isopropanol volume fraction in the eluent in the region of 0.3 to 5.0 vol.%, the observed behavior of the studied chromatographic systems is similar to the quasi-normal-phase HPLC pattern. According to the obtained thermodynamic data, benzene adsorption into HKUST-1 micropores from solutions with a vol.% of isopropanol in the range of 0.4 to 5.0 follows the unique entropy-driven mechanism previously described for the MIL-53(Al) framework. It was found that HKUST-1 loading in the composites and their preparation conditions have pronounced effects on their physicochemical properties and adsorption performance, including the adsorption mechanism. [ABSTRACT FROM AUTHOR]

Enantiomeric-enriched ferrocene-modified pyrazoles were synthesized via the reaction of the ferrocene alcohol, (S)-FcCH(OH)CH3 (Fc = ferrocenyl), with various pyrazoles in acidic conditions at room temperature within several minutes. X-ray structural data for racemic (R,S)-1N-(3,5-dimethyl pyrazolyl)ethyl ferrocene (1) and its (S)-enantiomer (S)-1 were determined. A series of racemic pyrazolylalkyl ferrocenes was separated into enantiomers by analytical HPLC on β- and γ-cyclodextrins (CD) chiral stationary phases. The quantum chemical calculations of interaction energies of β-CD were carried out for both (R)- and (S)-enantiomers. A high correlation between experimental HPLC data and calculated interaction energies values was obtained. [ABSTRACT FROM AUTHOR]

Graphical abstract A representative within a new class of chiral enol NiII complexes derived from a Schiff base of aminoacetone and (S)-2- N -(N -benzylprolinoylamino)benzophenone was prepared, and its performance in nucleophilic addition was estimated. The complex was inert towards aldehydes and activated C=C bonds but reacted with carboxylic anhydrides and di- tert -butyl acetylenedicarboxylate. An unusual Michael addition intermediate stabilized by the Ni–C bond was discovered in the latter reaction. [ABSTRACT FROM AUTHOR]

Ferrocenylalkyl 2-mercaptobenzimidazoles 3 (a – e) and 2-mercaptobenzo[d]thiazole-2(3H)-thiones 5 (a – e ) were prepared via the reaction of the α-(hydroxy)alkyl ferrocenes, FcCHR(OH) ( 1a – e ; Fc = ferrocenyl; R = H, Me, Et, i-Pr, Ph), either with thiobenzimidazole in acetone at room temperature in the presence of TFA (catalytic amounts), in yields of 55–74%, or with thiobenzothiazole in methylendicloride in presence of aqueous HBF 4 (equimolar amounts) at r.t., in yields of 41–58%. The structures, electrochemical properties and enantiomeric resolution 3a – e and 5a – e (using HPLC on modified amylose as chiral selector) were investigated. In cyclic voltammetry all studied compounds exhibited a reversible one-electron oxidation–reduction wave owing to the ferrocene–ferricenium redox couple with a positive shift (0.56–0.80 V) compared with that of ferrocene (0.50 V). X-ray determinations of molecular structures of 3-ferrocenylmethylbenzo[d]thiazole-2(3H)-thione ( 5a ) 3-ferrocenylethylbenzo[d]thiazole-2(3H)-thione ( 5b ) and 3-ferrocenylphenylmethylbenzo[d]thiazole-2(3H)-thione ( 5d ) were carried out. The toxicity and antitumor activity of N -(ferrocenylethyl)-2-thiobenzimidazole ( 3b ) were evaluated in vivo . Maximum tolerated dose (MTD) value for the compound 3b was found to be equal to 800 mg kg −1 . The effectiveness of compound under investigation against murine solid tumor system, carcinoma Ca755 (Ca755), was studied in a wide range of doses and significant antitumor effects were found. The index of tumor growth inhibition (TGI) on Ca755 equaled 87% in comparison with control. [ABSTRACT FROM AUTHOR]

The paper describes unexpected properties of hypercross-linked polystyrenes with ultimate cross-linking degrees of 300, 400, and 500%, where three, four, or five methylene links, respectively, could bind each polystyrene phenyl ring to its spacious neighbors. The polymers exhibit a strong electron spin resonance signal, unusual spectra in IR, UV, and visible ranges, and they are not typical dielectrics. The nonfunctionalized hypercross-linked polymers absorb significant amounts of inorganic acids, salts, and bases due to interactions of protons or other cations with electron-donating fragments of the aromatic network with the high extent of mutual connectivity and also due to dispersion interactions of anions with the polymer matrix. [ABSTRACT FROM AUTHOR]

The enantioselective synthesis of ring-substituted [ N-(hydroxy)amino](phenyl)methylphosphonic esters via asymmetric hydrogenation of the corresponding N-hydroxy- α-imino phosphonates with up to 90% ee was developed using catalytic amounts of palladium(II) acetate and ( R)-BINAP in 2,2,2-trifluoroethanol with a Brønsted acid as an activator. [ABSTRACT FROM AUTHOR]

Abstract: A simple and rapid procedure for the incorporation of nanosized Pd particles into hypercrosslinked polystyrene matrix was developed. The prepared catalyst has shown high activity in the coupling of aryl bromides and chlorides with phenylboronic acid, with water being the preferred solvent. The catalyst can be recycled two times without loss of activity. [Copyright &y& Elsevier]

Ferrocenyl(alkyl)azoles were synthesized in high yields by interaction of α-ferrocenylcarbinoles with azoles in aqueous–organic in the presence of HBF4 or by interaction of α-ferrocenylcarbinoles with N,N′-carbonyldiimidazole, N,N′-thionyldiimidazole, N,N′-thionyldibenzimidazole in boiling dichloromethane. The resulting enantiomers of ferrocenyl(alkyl)azoles and some carbinoles were separated using HPLC on silica bonded chiral stationary phases based on cyclodextrins and modified cellulose. [Copyright &y& Elsevier]

A number of pharmaceutically interesting optically active 1-arylethylphosphonates, including a phosphorus analogue of naproxen, has been synthesized with ee 92–95% via asymmetric hydrogenation under mild conditions using [Ir(cod)(phosphine oxazoline)]+ [BArF]− catalysts. [Copyright &y& Elsevier]

To date, metal-organic frameworks (MOFs) have been recognized as promising solid phases in high-performance liquid chromatography (HPLC). This research aimed to elucidate the role of the physico-chemical characteristics of the microporous HKUST-1 metal-organic framework in its operation as a selective adsorbent in HPLC. For this, the HKUST-1 samples were prepared by microwave-assisted synthesis and a solvothermal procedure. According to the chromatographic examinations, the HKUST-1 material synthesized in the microwave fields shows an efficient performance in the selective adsorption of aromatic compounds with different functionalities. This study revealed a significant impact of the preparation procedure on the mechanism of the liquid-phase adsorption on the HKUST adsorbents under conditions of the HPLC. An effect of the elution solvent with the different coordination ability to the Cu2+ sites in the HKUST-1 structure on the adsorption selectivity was observed. [ABSTRACT FROM AUTHOR]

A series of ferrocene‐modified amino acid methyl esters with pyrazole linker was prepared in good to quantitative yields starting from easy accessible ferrocene pyrazole carbaldehyde and amino acids in racemic and enantio enriched forms under reductive amination conditions (NaBH (OAc)3, reflux, 3 hr). The resulting enantiomers were resolved using analytical HPLC on modified cellulose or amylose as chiral selectors. In vivo electrophysiological experiments were performed in the CA1 field of the hippocampus on 3a Fc‐Gly, (L)‐3b Fc‐Ala, and (D)‐3b Fc‐Ala compounds. An increasing in the amplitudes of responses of local potentials (up to 25%) of the CA1 region in the studied groups was found after intraperitoneal administration of ferrocene compounds 3a and (D)‐3b compared with control rats treated with saline. [ABSTRACT FROM AUTHOR]

This is the first catalytic, most straightforward, and atom-economical approach to enantioenriched N-hydroxy-α-amino-phosphonates (II). [ABSTRACT FROM AUTHOR]