F:Flammable;
75-15-0Relevant academic research and scientific papers
Regularities of the property changes in the compounds EuLnCuS3 (Ln = La-Lu)
Ruseikina, Anna V.,Chernyshev, Vladimir A.,Velikanov, Dmitriy A.,Aleksandrovsky, Aleksandr S.,Shestakov, Nikolay P.,Molokeev, Maxim S.,Grigoriev, Maxim V.,Andreev, Oleg V.,Garmonov, Alexander A.,Matigorov, Alexey V.,Melnikova, Ludmila V.,Kislitsyn, Anatoliy A.,Volkova, Svetlana S.
, (2021/05/04)
This work contains the results of complex experimental research of the compounds EuLnCuS3 (Ln = La-Lu) enhanced by the DFT calculations. It is aimed at the data replenishment with particular attention to the revelation of regularities in the property changes, in order to extend the potential applicability of the materials of the selected chemical class. The ab initio calculations of the fundamental vibrational modes of the crystal structures were in good agreement with experimental results. The wavenumbers and types of the modes were determined, and the degree of the ion participation in the modes was also estimated. The elastic properties of the compounds were calculated. The compounds were found out to be IR-transparent in the range of 4000–400 cm–1. The estimated microhardness of the compounds is in the range of 2.68–3.60 GPa. According to the DSC data, the reversible polymorphous transitions were manifested in the compounds EuLnCuS3 (Ln = Sm, Gd-Lu): for EuSmCuS3 Tα?β = 1437 K, ΔНα?β = 7.0 kJ·mol-1, Tβ?γ = 1453 K, ΔНβ?γ = 2.6 kJ·mol-1; for EuTbCuS3 Tα?β = 1478 K, ΔНα?β = 1.6 kJ·mol-1, Tβ?γ = 1516 K, ΔНβ?γ = 0.9 kJ·mol-1, Tγ?δ = 1548 K, ΔНγ?δ = 1.6 kJ·mol-1; for EuTmCuS3 Tα?β = 1543 K, Tβ?γ = 1593 K, Tγ?δ = 1620 K; for EuYbCuS3 Tα?β = 1513 K, Tβ?γ = 1564 K, Tγ?δ = 1594 K; for EuLuCuS3 Tα?β = 1549 K, Tβ?γ = 1601 K, Tγ?δ = 1628 K. In the EuLnCuS3 series, the transition into either ferro- or ferrimagnetic states occurred in the narrow temperature range from 2 to 5 K. The tetrad effect in the changes of incongruent melting temperature and microhardness conditioned on rLn3+ as well as influencing of phenomenon of crystallochemical contraction were observed. For delimiting between space groups Cmcm and Pnma in the compounds ALnCuS3, the use of the tolerance factor t’ = IR(A)·IR(C) + a×IR(B)2 was verified.
Evolution of Structural, Thermal, Optical, and Vibrational Properties of Sc2S3, ScCuS2, and BaScCuS3 Semiconductors
Aleksandrovsky, Aleksandr S.,Andreev, Oleg V.,Azarapin, Nikita O.,Leonidov, Ivan I.,Maximov, Nikolai G.,Oreshonkov, Aleksandr S.,Razumkova, Illaria A.,Shestakov, Nikolai P.
, p. 3355 - 3366 (2021/08/23)
In the present work, we report on the synthesis of Sc2S3, ScCuS2 and BaScCuS3 powders using a method based on oxides sulfidation and modification of their properties. The crystal structures and morphology of samples are verified by XRD and SEM techniques. Thermal stability has been studied by DTA which has revealed that Sc2S3 decomposes to ScS through melting at 1877 K. ScCuS2 and BaScCuS3 melt incongruently at temperatures of 1618 K and 1535 K, respectively. The electronic structure calculations show that the investigated compounds are semiconductors with indirect band gap (Eg). According to the diffuse reflection spectroscopy, Sc2S3, ScCuS2 and BaScCuS3 are wide-bandgap semiconductors featured the Eg values of 2.53 eV, 2.05 eV and 2.06 eV, respectively. The band gap decreases with the introduction of copper (I) and barium cations into the crystal structure of the compounds. Variation of local structure has been verified by Raman and infrared spectroscopy. The calculated vibrational modes of ScCuS2 correspond to CuS4 and Sc?S layer vibrations, even though ScS6 octahedra-like structural units can be found in the structure.
Synthesis of copper(i) cyclic (alkyl)(amino)carbene complexes with potentially bidentate N^N, N^S and S^S ligands for efficient white photoluminescence
Romanov, Alexander S.,Chotard, Florian,Rashid, Jahan,Bochmann, Manfred
, p. 15445 - 15454 (2019/11/03)
The reaction of (Me2L)CuCl with either NaS2CX [X = OEt, NEt2 or carbazolate (Cz)] or with 1,3-diarylguanidine, 1,3-diarylformamidine or thioacetaniline in the presence of KOtBu affords the corresponding S- or N-bound copper complexes (Me2L)Cu(S^S) 1-3, (Me2L)Cu(N^N) 4/5 and (Me2L)Cu(N^S) 6 (aryl = 2,6-diisopropylphenyl; Me2L = 2,6-bis(isopropyl)phenyl-3,3,5,5-tetramethyl-2-pyrrolidinylidene). The crystal structure of (Me2L)Cu(S2CCz) (3) confirmed the three-coordinate geometry with S^S chelation and perpendicular orientation of the carbene and S^S ligands. On heating 3 cleanly eliminates CS2 and forms (Me2L)CuCz. The N-bound complexes show strongly distorted T-shaped (4) or undistorted linear (5) geometries. On excitation with UV light the S-bound complexes proved non-emissive, while the guanidinato and formamidinato complexes are strongly phosphorescent, with excited state lifetimes in the range of 11-24 μs in the solid state. The conformationally flexible formamidinato complex 5 shows intense green-white phosphorescence with a solid-state quantum yield of >96%.
Synthesis and Upconversion Luminescence in LaF3:Yb3+, Ho3+, GdF3: Yb3+, Tm3+ and YF3:Yb3+, Er3+ obtained from Sulfide Precursors
Razumkova, Illariia A.,Denisenko, Yuriy G.,Boyko, Andrey N.,Ikonnikov, Denis A.,Aleksandrovsky, Aleksandr S.,Azarapin, Nikita O.,Andreev, Oleg V.
, p. 1393 - 1401 (2020/01/02)
Rare earth fluorides are mainly obtained from aqueous solutions of oxygen-containing precursors. Probably, this method is simple and efficient, however, oxygen may partially be retained in the fluoride structure. We offer an alternative method: obtaining fluorides and solid solutions based on them from an oxygen-free precursor. As starting materials, we choose sulfides of rare-earth elements and solid solutions based on them. The fluorination is carried out by exposure to hydrofluoric acid of various concentrations. The transmission electron microscopy images revealed the different morphologies of the products, which depend on the concentration of the fluorinating component (HF) and the host element. The solid solution particle size varied from 30–35 nm in the case of GdF3:Yb3+, Tm3+ (4 % HF) to larger structures with dimensions exceeding 200 nm, such as that for LaF3:Yb3+, Ho3+ (40 % HF). The thermal characteristics, such as the temperatures of the transitions and melting and enthalpies, were determined for the solid solutions and simple fluorides. Applicability of the materials obtained as biological luminescent markers was tested on the example of upconversion luminescence, and good upconversion properties were detected.
PROCESS FOR CONVERSION OF DIMETHYL SULFIDE TO METHYL MERCAPTAN
-
Paragraph 0086-0089, (2018/03/09)
Disclosed herein are systems and processes involving the catalyzed cleavage reaction of dimethyl sulfide to methyl mercaptan. The catalyzed cleavage reaction can be a standalone system or process, or can be integrated with a methyl mercaptan production plant.
Y2S3 – Y2O3 phase diagram and the enthalpies of phase transitions
Andreev,Pimneva
, p. 24 - 29 (2018/04/17)
A phase diagram of the Y2S3-Y2O3, system has been defined from 1000 K to melts for the first time; the enthalpies of phase transitions in the systems have been determined. The monoclinic phase δ-Y2S3 (P21/m, a = 1.7523(8) nm, b = 0.4010(9) nm, с = 1.0170(7) nm, β = 98.60(6)°; microhardness H = 411 ± 7 HV) transforms at 1716 ± 7 K to the unquenchable high-temperature phase ξ-Y2S3, ΔН = 29 ± 6 J/g (7.9 KJ/mol) as determined by DSC. The quenching can't latch the Y2S3-phase. The melting point of Y2S3 is 1888 ± 7 K; ΔН = 150 ± 28 J/g (41.1 KJ/mol). Y2OS2 has a monoclinic structure (P21/c, а = 0.8256(8) nm, b = 0.6879(8) nm, с = 0.6848(8) nm, β = 99.52(6), Н = 491 ± 13 HV) and melts incongruently at 1790 ± 8 K, ΔН = 190 ± 45 J/g (52 KJ/mol) by the scheme Y2OS2 ? Y2O2S + L (16 mol% Y2O3). Y2O2S has a hexagonal structure (a = 0.3784(5) nm, c= 0.6584(4) nm, Н = 654 ± 7 HV). Its congruent melting temperature is 2350 ± 40 K as determined by visual polythermal analysis (VPTA). The eutectic formed by Y2S3 and Y2OS2 phases has the composition 14.0 ± 0.5 mol% Y2O3 (0.58Y2S3 + 0.42Y2OS2) and melting temperature 1770 ± 6 K; ΔН = 215 ± 39 J/g. Between Y2O2S and Y2O3 phases, there is a eutectic with the coordinates 80 ± 1 mol% Y2O3 (0.6Y2O2S + 0.4Y2O3) and melting temperature 2150 ± 35 K (VPTA).
METHOD FOR PREPARING METHYL MERCAPTAN
-
Paragraph 0107-0110, (2017/06/27)
The present invention relates to a method for preparing methyl mercaptan, in batches or continuously, preferably continuously, said method including at least the following steps: a) reacting at least one hydrocarbon feedstock in the presence of hydrogen sulphide (H2S) and optionally sulphur (S) such as to form carbon disulphide (CS2) and hydrogen (H2); b) reacting said carbon disulphide (CS2) by hydrogenation in the presence of said hydrogen (H2) obtained in step a) such as to form methyl mercaptan (CH3SH), hydrogen sulphide (H2S) and possibly hydrogen (H2); c) optionally recirculating said hydrogen sulphide (H2S) formed during step b) to step a); and d) recovering the methyl mercaptan.
Investigation of pyramidal inversion of nitrogen atom in carbamate and thiocarbamate ions formed at the reaction of СО2, СOS, CS2 with 2-aminoethanol
Talsi,Evdokimov
, p. 1630 - 1636 (2017/12/29)
Dynamic NMR was applied to measuring the value ΔG≠ characterizing the height of the barrier to the pyramidal inversion of the nitrogen atom in carbamate and thiocarbamate anions formed at the reaction of 2-aminoethanol with CO2 and COS. The refinement was introduced in formerly suggested cyclic structures of anions containing an intramolecular hydrogen bond NHO(S), which contradicted the found large values of the barrier of inversion (ΔG≠ ～ 70 kJ mol–1). The hydrogen bond in the cyclic anions of carbamates and thiocarbamates is two-electron and three-center. Analogous cyclic structure with a multicenter hydrogen bond does not form in the case of dithiocarbamate anion that is the product of 2-aminoethanol reaction with CS2.
Kinetic Insights into Hydrogen Sulfide Delivery from Caged-Carbonyl Sulfide Isomeric Donor Platforms
Zhao, Yu,Henthorn, Hillary A.,Pluth, Michael D.
supporting information, p. 16365 - 16376 (2017/11/22)
Hydrogen sulfide (H2S) is a biologically important small gaseous molecule that exhibits promising protective effects against a variety of physiological and pathological processes. To investigate the expanding roles of H2S in biology, researchers often use H2S donors to mimic enzymatic H2S synthesis or to provide increased H2S levels under specific circumstances. Aligned with the need for new broad and easily modifiable platforms for H2S donation, we report here the preparation and H2S release kinetics from a series of isomeric caged-carbonyl sulfide (COS) compounds, including thiocarbamates, thiocarbonates, and dithiocarbonates, all of which release COS that is quickly converted to H2S by the ubiquitous enzyme carbonic anhydrase. Each donor is designed to release COS/H2S after the activation of a trigger by activation by hydrogen peroxide (H2O2). In addition to providing a broad palette of new, H2O2-responsive donor motifs, we also demonstrate the H2O2 dose-dependent COS/H2S release from each donor core, establish that release profiles can be modified by structural modifications, and compare COS/H2S release rates and efficiencies from isomeric core structures. Supporting our experimental investigations, we also provide computational insights into the potential energy surfaces for COS/H2S release from each platform. In addition, we also report initial investigations into dithiocarbamate cores, which release H2S directly upon H2O2-mediated activation. As a whole, the insights on COS/H2S release gained from these investigations provide a foundation for the expansion of the emerging area of responsive COS/H2S donor systems.
Photochemical properties and structure characterization of (BiO)2CO3 nanowires doped with alkaline-earth metal ions
Cui, Kuixin,He, Yuehui,Guo, Yujiao,Jin, Shengming
, p. 111 - 118 (2017/03/02)
The photoluminescence (PL) properties and photocatalytic activities of pure (BiO)2CO3 nanowires and (BiO)2CO3 nanowires doped with alkaline-earth metal ions (Mg2+, Ca2+, and Sr2+
