New ammonium ionic liquids with a ferrocenylmethyl radical in the cation with different long hydrophobic chains (C7H15, C12H25, and C16H33) were prepared. The thermal stability of the compounds in air in the temperature range 20–500°C was studied in comparison with an ionic liquid with the benzyl radical in the cation. A higher thermal stability of dimethylferrocenylmethylalkylammonium chlorides was shown in comparison with benzalkonium.
Sodium polymetaphosphate (Graham’s salt) is a hydrolytically unstable compound; when stored in relatively humid warehouses, the reagent quickly ages, which is manifested in the loss of its consumer properties, including the rate of dissolution in water and the ability to form micelles. To improve hydrolytic stability, Graham’s salt was modified with 4,5-dihydroxy-1,3-bis(hydroxymethyl)imidazolidinone. Depending on the molar ratios of Graham’s salt and modifier, oligomers with different functional groups were obtained. Depending on the molar ratios of Graham’s salt and modifier, oligomers with different terminal functional groups were obtained. It was found that oligomers containing terminal methylol groups are characterized by high hydrolytic stability. They dissolve well in water and promote foaming. The average molecular weights of the obtained oligomers were determined.
This review focuses on the latest advancements in combustible components of solid rocket fuel and explores the potential use of hydrides, nitriles, and tetrazoles as its components.
For a long time now, cigarette smoking has been recognized as a primary source of toxic chemical exposure for people. Among said toxic chemicals, VOCs are identified as being the highest contributing category to the overall toxicity of cigarette smoke. Thus, in this review an identification of the various VOCs present in cigarette smoke (mainstream, sidestream and environmental tobacco smoke) was first conducted, followed by a survey of the different factors affecting their emission level. Then, a study of the presently used techniques for the abatment of cigarette smoke-derived VOCs was performed. Finally, an assesment of some potentially interesting catalytic systems for the reduction of VOCs emission was carried out.
The ability of the sorbent-mineralizer to irreversibly bind carbon dioxide in both fresh and sea water forming chemically and thermally stable carbonate structural forms based on melilite silicate Ca2[Al2Mg,Si]Si2O7 has been discovered. The latter is similar to natural minerals, therefore it is environmentally friendly. The influence of the chemical background of the sorbent-mineralizer on the process of its carbonization in aqueous media has been revealed. It has been shown that ({text{CO}}_{3}^{{2 - }}) groups in the composition of the initial sorbent-mineralizer are the primary active centers during the surface phase formation of carbonized calcium and magnesium aluminosilicates in aqueous media. It has been established that the thermal stability of the structure of carbonized calcium and magnesium aluminosilicates is maintained after heating to 1000°C. The formation of carbonized calcium and magnesium hydroaluminosilicates in seawater is accompanied by an increase in pH, which characterizes the ability of the sorbent-mineralizer to regulate the acid-base balance and maintain carbonate balance in the hydrosphere. In addition to the irreversible binding of CO2, the sorbent-mineralizer reveals the ability to irreversibly sorption of impurity cations Pb2+, Cu2+, Zn2+, as well as phosphorus in sea water.
Eight molecules of the homologous series of acetone and eight molecules of the homologous series of thioacetone were optimized by the exchange-correlation hybrid functional B3LYP. Within the framework of the quantum theory of atoms in molecules QTAIM, the integral electronic characteristics of groups were obtained. Group charges, volumes and energies in the considered classes of organic compounds were compared and the difference in the redistribution of electron density of molecules was shown, depending on the type of functional group: thionic or carbonyl. The inductive effect and steric influence of C(S) and C(O) groups on neighboring methyl and methylene fragments were characterized; a general qualitative scale of group electronegativity was constructed.
The processes of phase formation enabling the separation of water isotopologues in their solutions are studied and the physicochemical factors facilitating the extraction of heavy-water isotopologues are identified. The thermodynamic conditions for obtaining heavy water and heavy-oxygen water, as well as the optimal raw-material sources for their production, are determined. The productivity of the application of tritiated water, involving its electrosonolysis with the release of molecular tritium, is justified.
During recrystallization from benzene or toluene of the products of interaction of triarylantimony or triarylbismuth with carboxylic acids, phenol, or oxime in the presence of tert-butyl hydroperoxide (molar ratio 1 : 2 : 1, diethyl ether, 24°C, 24 h), minor products, adducts of aryl compounds of antimony or bismuth of the Ar3MX2 type with carboxylic acids, phenol, and oxime are isolated. According to X-ray structural analysis conducted at 293 K using an automatic D8 Quest Bruker four-circle diffractometer (two-coordinate CCD detector, Mo Kα radiation, λ = 0.71073 Å, graphite monochromator), the metal atoms in the crystals of m-Tol3Sb[OC(O)C6H3F2-2,5]2 ⋅ HOC(O)C6H3F2-2,5 (1) [C42H31O6F6Sb, M 867.42; triclinic system, symmetry group P(bar {1}); cell parameters a = 8.78(5) Å, b = 13.10(6) Å, c = 16.64(8) Å; α = 102.86(19)°, β = 99.3(2)°, γ = 98.0(3)°; V = 1813(16) Å3; Z 2; reflection index intervals –7 ≤ h ≤ 7, –11 ≤ k ≤ 11, –14 ≤ l ≤ 14; total reflections 14 149; independent reflections 2603; Rint 0.0284; GOOF 1.049; R1 = 0.0348, wR2 = 0.0938; residual electron density 0.55/–0.42 e/Å3], p‑Tol3Bi[OC(O)C6HF4-3,4,5,6]2 ⋅ HOC(O)C6HF4-3,4,5,6 (2) [C42H25O6F12Bi, M 1062.60; triclinic system, symmetry group P(bar {1}); cell parameters a = 12.246(11) Å, b = 12.976(18) Å, c = 14.391(13) Å; α = 68.27(4)°, β = 69.89(3)°, γ = 86.11(5)°; V = 1990(4) Å3; Z 2; reflection index intervals –15 ≤ h ≤ 15, ‒16 ≤ k ≤ 16, –18 ≤ l ≤ 18; total reflections 48 542; independent reflections 9207; Rint 0.0321; GOOF 1.136; R1 = 0.0322, wR2 = 0.0648; residual electron density 1.81/–1.08 e/Å3], [(2-MeO-5-BrC6H3)3SbOC6H4Br-4]2O ⋅ 2HOC6H4Br-4 (3) [C66H54Br10O11Sb2, M 2065.69; monoclinic system, symmetry group C21/c; cell parameters a = 12.017(14) Å, b = 25.54(3) Å, c = 13.181(18) Å; β = 116.71(5)°; V = 3613(8) Å3; Z 2; reflection index intervals –13 ≤ h ≤ 13, –27 ≤ k ≤ 27, –12 ≤ l ≤ 12; total reflections 29 461; independent reflections 4545; Rint 0.0656; GOOF 1.062; R1 = 0.0565, wR2 = 0.12
The initiated oxidation of 4,7-dihydro-1,3-dioxepine and 2-isopropyl-4,7-dihydro-1,3-dioxepine with molecular oxygen in the liquid phase (323 K) was studied. Microvolumetry, IR Fourier-transform spectroscopy, 1H NMR spectroscopy, potentiometry in combination with computer simulation and quantum chemical calculations were used. It was found that during the oxidation process, continuation of chains is realized due to the abstraction of a hydrogen atom by the peroxyl radical from the CH bond of the cycloolefin weakened by conjugation.
Quaternary ammonium salts (QASs) containing gem-dichlorocyclopropane and 1,3-dioxacycloalkane fragments were prepared in 40–90% yields based on pyridine, hexamethylenetetramine, and tertiary amines. The structures of the obtained salts were identified by 1H and 13C NMR spectroscopy. The antibacterial activity of QAS against a bacterial strain (Escherichia coli, Klebsiella pneumoniae, S. aureus, and Acinobacter Baumanii) were assessed. Among the salts tudied, leader compounds were identified that exhibited high antibacterial activity.
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