Selective Synthesis of 2,5‐Diformylfuran by Sustainable 4‐acetamido‐TEMPO/Halogen‐Mediated Electrooxidation of 5‐Hydroxymethylfurfural

A new method was developed for the selective gram‐scale synthesis of 2,5‐diformylfuran (DFF), which is an important chemical with a high application potential, via oxidation of biomass‐derived 5‐hydroxylmethylfurfural (HMF) catalyzed by 4‐acetylamino‐2,2,6,6‐tetramethylpiperidine‐1‐oxyl (4‐AcNH‐TEMPO) in a two‐phase system consisting of a methylene chloride and aqueous solution containing sodium hydrogen carbonate and potassium iodide. The key feature of this method is the generation of the I₂ (co‐)oxidant by anodic oxidation of iodide anions during pulse electrolysis. In addition, the electrolyte can be successfully recycled five times while maintaining a 62–65 % yield of DFF. This novel method provides a sustainable pathway for waste‐free production of DFF without the use of metal catalysts and expensive oxidants. An advantage of electrooxidation is utilized in the preparation of demanding chemical.     

Mass spectrometry of π-complexes of transition metals XIX. Cymantrene-cyclopentadienylmetal carbonyl derivatives

Mass spectra of the complexes π-C₅H₅M(CO)_nXC₅H₄Mn(CO)₃ have been studied. The presence of intense ions C₅H₅M(CO)_nMn⁺ suggests that synthesis of new compounds with charged bivalent manganese of π-C₅H₅W(CO)₃Mn⁺X^? type is possible. In addition, the presence of these ions indicates preferential loss of the first three carbonyl groups from the manganese atom.     

Formation of Carbon Materials by the Oxidative Pyrolysis of Methane on Resistive Catalysts

Kinetics and Catalysis - This review describes the regularities of the synthesis of nanostructured carbon materials (NCMs) based on the pyrolysis of methane on the surface of conductive materials...     

The minimality of certain decidability conditions for Boolean algebras

We complete our study of the decidability of Boolean algebras in terms of computability of a certain sequence of canonical ideals. We present a proof of the minimality of the conditions obtained for the decidability of Boolean algebras of all elementary characteristics.     

On the mechanism of electrochemical dispersion of platinum under the action of alternating current

The behavior of platinum electrodes in alkali solutions under the action of pulse alternating current was studied. A mechanism of electrochemical dispersion of platinum was proposed. An important step of the mechanism is the discharge and cathodic insertion of alkali metal cations into the crystalline lattice of platinum followed by the decomposition of intermetallic compound Pt _m Na upon the interaction with water. Dispersion is facilitated by the presence of an oxide film on the platinum surface formed in the anodic period of pulses, a periodical alternation of electrode polarity resulting in the electrochemical injection of vacancies from the metal bulk to the surface, and hydrogen and oxygen formation in the corresponding periods.     

Copolymers of 2-Deoxy-2-Methacrylamido-D-Glucose with Aminoacrylates and Allylamine Hydrochloride

New polyvinylsaccharides containing primary or tertiary amino groups were synthesized by radical copolymerization of 2-deoxy-2-methacrylamido-D-glucose (MAG) with 2-(dimethylamino)ethyl methacrylate, 2-(diethylamino)ethyl methacrylate (DEAEM), or allylamine hydrochloride. The reactivity ratios of comonomers were determined. The effect of copolymer composition on the conformational properties of macromolecules was detected. For MAG-DEAEM copolymers with DEAEM unit content more than 60 mol-% the increase of degree of ionization causes conformational transition at α = 0.3 to 0.7 from compact polymer coil to loose coil due to the electrostatic repulsion of charged amino groups. The increase of MAG content in copolymers is accompanied by a decrease of their cytotoxicity.