Redox conversions of new antiviral drug Triazavirin®: electrochemical study and ESR spectroscopy

Russian Chemical Bulletin - The results of studying electrochemical conversions of 7-R-3-X-1,2,4-triazolo[5,1-c][1,2,4]-triazin-4-ones (Triazavirin® and its derivatives) using cyclic...     

Tensimetric Study of the Tris(2,2,6,6-tetramethylheptan-3,5-dionato)yttrium(III) Dissociation in a Gas Phase

Russian Journal of General Chemistry - The saturated and unsaturated vapor pressures of tris(2,2,6,6-tetramethylheptane-3,5-dionato)yttrium(III), Y(thd)3, were measured by the static method with a...     

Synthesis of Salts and Ionic Liquids on the Basis of 2-Aminothiazolium Cations

Russian Journal of General Chemistry - The base-free reactions of 2-aminothiazole with α-iodoketones were studied. Depending on the reaction conditions, linear or cyclic 2-aminothiazolium...     

Role of Water in the Photochemical Synthesis of Methyl 12-Oxo-6,12-dihydroazepino[2,1-b]quinazoline-8-carboxylates

Russian Journal of General Chemistry - Methyl 12-oxo-6,12-dihydroazepino[2,1-b]quinazoline-8-carboxylate and methyl 3H-azepin-2(1H)-one-5-carboxylate were synthesized by photoinduced...     

A New Metal-Organic Framework: Product of Solvothermal Synthesis in 3D-Printed Autoclaves

Russian Journal of Coordination Chemistry - A new metal-organic framework {Zn4(BDC)3(OAc)2(DMF)4} (BDC = terephthalate anion) was synthesized under solvothermal conditions in a 3D-printed...     

TBAI/TBHP-Catalyzed Synthesis of [1,2,4]Triazolo[4,3-a]pyridines and 3,5-Diaryl-1,2,4-oxadiazoles via Oxidative Cleavage of C=C Double Bond

Russian Journal of Organic Chemistry - A simple and efficient protocol has been described for the synthesis of [1,2,4]triazolo[4,3-a]pyri­dines and 3,5-disubstituted-1,2,4-oxadiazoles by...     

Efficiency analysis of thermosyphon solar flat plate collector with low mass concentrations of ND–Co3O4 hybrid nanofluids: an experimental study

Journal of Thermal Analysis and Calorimetry - In the present study, the thermal efficiency, convective heat transfer and friction factor analysis are investigated for a flat plate solar collector...     

Nature and strength of weak intermolecular interactions with metal atoms in crystals of square-planar nickel(<Emphasis Type="SmallCaps">ii</Emphasis>) complexes

The results of geometric analysis of 588 crystal structures of square-planar nickel complexes containing short intermolecular Ni…X contacts (X is a non-metal atom) are reported. The frequency of occurrence of Ni…X interactions of a particular type was evaluated depending on the nature of the X atom and geometric characteristics. The promolecular functions RDG and sign(λ₂)?ρ(r) were used to analyze the character of Ni…X interactions in attractive/repulsive terms. The relative strength of these interactions was determined as the function of the nature of the X atom and the direction of charge transfer.     

Quantum chemical studies of azoles

The results of theoretical search for model transition states of the electrophilic substitution reaction in 2H-tetrazole (1) without the preliminary formation of N-protonated azolium salts are presented for two routes that were previously suggested by the authors and thermodynamically investigated: A, the attack of molecule 1 by the nucleophile (HO^–(aq)) to form the anion to which the electrophile H₃O⁺(aq)) is added and B, the attack of molecule 1 by the same electrophile followed by the addition of the same nucleophile to the specifically solvated protonated species formed in the preceding reaction step. The calculations were performed using the DFT/B3LYP/6-31G(d) method and the scanning procedure of the potential energy surface (PES). Both steps of route A turned out to be nearly barrierless, while in route B only its first step is barrierless and the second one is conjugated with passing an activation barrier of ～45 kcal mol^–1 between non-interacting or weakly interacting reactants and electrophilic substitution products. Unlike the specifically solvated protonated species of 1H-tetrazole in an aqueous solution, a similar species of 2H-tetrazole does not form a prereaction complex with the attacking nucleophile (HO^–(aq)) and the five-membered ring is destroyed in fact in the nitrogen-containing reaction product formed after passing the activation barrier. The optimized structure of the transition state differs strongly from the nitrogen-containing structure of the reaction product with the destroyed ring, which was found by scanning of the PES.     

Addition of phenylacetylene and camphor to the complex [(dpp-bian)Eu(dme)<Subscript>2</Subscript>] (dpp-bian is the 1,2-bis[(2,6-diisopropylphenyl)imino]acenaphthene dianion)

The reduction of 1,2-bis[(2,6-diisopropylphenyl)imino]acenaphthene (dpp-bian) with an excess of europium metal in 1,2-dimethoxyethane (dme) produces a divalent europium complex with the dpp-bian dianion, [(dpp-bian)Eu(dme)₂] (1). The reactions of 1 with phenyl-acetylene and camphor proceed via protonation of the diimine ligand to form the monomeric amido-amino complexes of divalent europium — [H(dpp-bian)Eu(C≡CPh)(dme)₂] (2) and [H(dpp-bian)Eu(camphor)(dme)₂] (3), respectively. Compounds 2 and 3 were characterized by IR spectroscopy and elemental analysis. Their molecular structures were determined by X-ray diffraction. Compounds 2 and 3 were shown to be monomeric seven-coordinate europium(ii) complexes with terminal phenylethynyl and enol ligands, respectively. According to the IR spectroscopic data, the terminal ligands in complexes 2 and 3 undergo tautomerization involving backward proton transfer from the amido-amino ligand to the substrate. The magnetic moment of compound 2 (8.03 μB) remains constant in the temperature range of 4—300 К and confirms the presence of divalent europium.