High-boiling Solvent Research Articles

Synthesis of Needlelike and Platelike SnS Active Materials in High-Boiling Solvents and Their Application to All-Solid-State Lithium Secondary Batteries

Tin sulfide (SnS) particles were synthesized by thermal decomposition of tin acetate in a mixed solution of 1-dodecanethiol, one of coordinating solvents such as trioctylphosphine and oleylamine, and 1-octadecene as a noncoordinating solvent at 280 °C for 2 h. The morphology of the obtained SnS particles was determined by transmission electron microscopy. Needlelike SnS particles were obtained by using trioctylphosphine as a coordinating solvent. On the other hand, platelike SnS particles were obtained by using oleylamine. The SnS particles were formed by diffusion of sulfur derived from 1-dodecanethiol into Sn particles. In addition, the aspect ratio of needlelike SnS particles was affected by the amount of 1-dodecanethiol as a sulfur source. The all-solid-state cells using SnS particles with the different morphology as an active material were fabricated. The initial discharge capacity of the all-solid-state cell using needlelike SnS particles as an active material was ca. 1000 mAh g–1, which was larger than that of the cell with platelike SnS particles under the current density of 0.13 mA cm–2 at 25 °C.

The influence of synthetic conditions on optical properties of cadmium selenide quantum dots

In this work we consider the technique used to prepare CdSe quantum dots (QDs) both in a high-boiling solvent (octadecene) and in an aqueous solution. It has been shown that, if octadecene is used as a medium for synthesis, the increase in synthetic temperature and reaction time leads to a substantial decrease in the QDs trap luminescence intensity. In addition, an increase in the synthesis temperature reduces the scatter of particles in sizes. In addition to the hydrofobic QDs, CdSe QDs have also been synthesized in an aqueous solution using mercaptopropionic acid as a stabilizer. Using these QDs as an example, the possibility of increasing the stability of QDs covered by mercaptopropionic acid in the presence of sodium sulfite has been shown for the first time. The role of sodium sulfite consists of the chemical binding of dissolved oxygen.

Kinetics of bagasse delignification by using high-boiling solvent

Kinetic modeling of lignin removal under conditions of high-boiling solvent (HBS, i.e. 1,4-butanediol) auto-catalyzed pulping of bagasse has been studied. The experimental data were collected based on the absorption of dissolved lignin in black liquor at a wavelength of 320 nm, which can eliminate the interferences arising from furfural (F) and 5-hydroxymethyl furfural (HMF) generated during pulping. The results indicated that the delignification process consists of two distinct phases. The initial phase, involving a very fast reaction, is followed by a rather slow second phase. The delignification equation was determined as: D=87.71×C0.8982× (1-e-1.757t) ×100%, which is valid within an HBS concentration range of 50% to 80% and can be used for predict the lignin removal from bagasse by HBS pulping.

Morphology control of copper indium disulfide nanocrystals

ABSTRACTIn this report, we present a hot-injection strategy for the synthesis of CuInS2 (CIS) nanocrystals with hexagonal, pyramidal and nanorod shapes. For that purpose copper (I) and indium (III) acetates were dissolved in oleylamine as a high-boiling solvent. Tert-dodecanethiol (t-DDT) was used as a sulfur source. It was mixed with 1-dodecanothiol (1-DDT) and injected at a high temperature. The presence of the second dodecanethiol was necessary to control the growth of the synthesized nanocrystals. We observed a strong influence of the t-DDT amount on the morphology of the CIS nanocrystals. By the variation of the injected solution uniform CIS nanorods with different aspect ratio and size were obtained.

Synthesis of nanosized nickel sulfide in high-boiling solvent for all-solid-state lithium secondary batteries

Nickel sulfide nanoparticles were synthesized by thermal decomposition of nickel acetylacetonate in a mixed solution of 1-dodecanethiol and a high-boiling solvent. The crystal phase and morphology of the obtained samples by changing the reaction time, reaction temperature, and the kind of the solvents were characterized by X-ray diffraction measurements and transmission electron microscopy. By using oleylamine as a coordinating solvent, Ni9S8 nanorods with the size of about 100 nm were obtained at 280 °C for 5 hours. On the other hand, NiS nanoparticles with the size of about 50 nm were obtained by using 1-octadecene as a noncoordinating solvent. Nickel sulfide crystals with different phase and morphology were obtained by selecting the solvent. The all-solid-state cells using NiS nanoparticles with the size of about 50 nm as active materials were fabricated. The 80Li2S·20P2S5 (mol%) glass–ceramic was used as a solid electrolyte. The cell Li–In/NiS exhibited the initial discharge capacity of 780 mA h g−1 at 0.13 mA cm−2 and the good cycle performance during 20 cycles.

Synthesis of Ferrite Nanocrystals Stabilized by Ionic-Liquid Molecules through a Thermal Decomposition Route

A series of M(x) Fe(3-x) O(4) (M=Fe, Co, Ni, Zn; 0≤x≤1) ferrite nanocrystals stabilized by ionic-liquid molecules have been successfully synthesized through a thermal decomposition route. Instead of the widely used long-chain lipid surfactants and high-boiling solvents, the ionic-liquid molecules not only played the role of surfactants, but also served as reaction and dispersion media simultaneously in the preparation of ferrite nanocrystals. Due to their good fluidity under magnetic fields and high ionic conductivity, the ionic-liquid molecules and M(x) Fe(3-x) O(4) ferrite nanocrystal-based conducting ferrofluids were successfully used as electrolytes in an AC circuit. The open or closed state of the circuit was directly controlled by moving a permanent magnet so as to tune the position of the ferrofluids, and consequently, resulted in the "off" or "on" state of the four indicative yellow-light-emitting diodes. These results demonstrate that the conducting ferrofluids successfully play the role of "magnetic switch".

Optical and electrical properties of pure and Ni-modified ZnS nanocrystals

ZnS and Ni doped ZnS nanoparticles were synthesized through chemical precipitation method using a high-boiling solvent. The nanocrystillanity of the prepared nanostructures is confirmed by X-ray diffraction (XRD). The mean crystal size obtained by full width half maxima (FWHM) analysis is 3.2 nm for ZnS and 4.3 nm for ZnS:Ni. An optical absorption study conducted in UV-vis range 150-800 nm reveals the transparency of these nanocrystals in entire visible range but not in ultraviolet range. The results based on optical analysis yield band gap values as 3.92 eV for ZnS and 3.88 eV for ZnS:Ni nanoparticles. The electrical resistivity data reveals semiconducting behaviour to both compositions. Fitting of resistivity data in Mott's variable range hopping model (VRH) shows that nickel (1.5%) doping in ZnS reduces gap parameters from 4.78 to 4.22 eV. Based on this model the carrier density, energy gap and hopping distances are calculated for both pure and Ni modified nanocrystals.

Solution-Phase Synthesis of Heteroatom-Substituted Carbon Scaffolds for Hydrogen Storage

This paper reports a bottom-up solution-phase process for the preparation of pristine and heteroatom (boron, phosphorus, or nitrogen)-substituted carbon scaffolds that show good surface areas and enhanced hydrogen adsorption capacities and binding energies. The synthesis method involves heating chlorine-containing small organic molecules with metallic sodium at reflux in high-boiling solvents. For heteroatom incorporation, heteroatomic electrophiles are added to the reaction mixture. Under the reaction conditions, micrometer-sized graphitic sheets assembled by 3-5 nm-sized domains of graphene nanoflakes are formed, and when they are heteroatom-substituted, the heteroatoms are uniformly distributed. The substituted carbon scaffolds enriched with heteroatoms (boron ∼7.3%, phosphorus ∼8.1%, and nitrogen ∼28.1%) had surface areas as high as 900 m(2) g(-1) and enhanced reversible hydrogen physisorption capacities relative to pristine carbon scaffolds or common carbonaceous materials. In addition, the binding energies of the substituted carbon scaffolds, as measured by adsorption isotherms, were 8.6, 8.3, and 5.6 kJ mol(-1) for the boron-, phosphorus-, and nitrogen-enriched carbon scaffolds, respectively.

ChemInform Abstract: Optimization of the Synthesis of 2‐Phenyl‐1,2,3‐triazole.

The synthesis of 2-phenyl-1,2,3-triazole by the cyclization of glyoxal phenylosazone in high-boiling solvents in the presence of copper triflate catalyst has been optimized. The structure of the product was confirmed by data of IR, 1H, 13C, and 15N NMR spectroscopy, mass spectrometry, and elemental analysis.

Temperature-resolved synchrotron X-ray diffraction of nanocrystalline titania in solvent: the effect of Cr–Sb and V–Sb doping

Nanocrystalline titania pigments were produced by high temperature-forced hydrolysis in a coordinating high-boiling solvent (and water for reference). The effect of synthesis conditions and co-doping with Cr–Sb and V–Sb on particle size and anatase-to-rutile transformation (A → R) was studied by temperature-resolved synchrotron X-ray diffraction. The experiments were performed directly on low concentration (3.5 vol.%) as-synthesized suspensions of titania nanoparticles (up to 230 °C) and on the corresponding dried powders (up to 950 °C). Crystallite size of as-synthesized nano-anatase is around 20 nm (glycol) or 70 nm (water); it exhibits a slow growth rate up to the onset temperature of the A → R. Phase composition and crystallite size are drastically influenced by both synthesis conditions and doping. Synthesis in water resulted in the simultaneous occurrence of anatase and brookite; transformation into rutile begins early but with a slower rate with respect to glycol-based samples. Doping affected the A → R, whose onset temperature in undoped titania (700 °C) was lowered to 650 °C (V–Sb) or prevented up to 950 °C (Cr–Sb). Both (V–Sb) and (Cr–Sb) dopings reduced the volume thermal expansion rate of anatase.

Torsionally Controlled Electronic Coupling in Mixed-Valence Oxodimolybdenum Nitrosyl Scorpionates - a DFT Study

The density functional theory (DFT) method has been used to study the electronic communication in strongly interacting oxo-bridged di-{Mo(II,I)(NO(+))}(3+,2+) complexes stabilized by tris(3-methylpyrazol-1-yl)borate, [Tp(Me)](-) (dihydroxy 1' and its modified analogs), having fully localized valences on the two Mo centers (Class I), despite a short (ca. 3.8 A) Mo...Mo distance. Structural and electrochemical (separation between the redox potentials Delta(red/ox)E(1/2)) properties and IR spectra (in particular the nu(NO) frequencies) obtained from the B3LYP calculations for 1' are successfully related to experimental values. Strongly twisted geometry with the (O)N-Mo1...Mo2-N(O) angle close to 90 degrees (confirmed by DFT modeling performed for 1'(-1,0,+1) and X-ray diffraction study of [{Mo(NO)(Tp(Me2))(OH)}(2)(mu-O)](-) (1) presented herein) is a common, though so far not fully understood, structural feature of this class of mu-oxo species, in contrast to the closely related {Mo(V)(=O)}(3+) analogs. This study shows that the orthogonality of the local equatorial planes for the two Mo centers may be rationalized by the electronic structure, namely from the balance between the destabilizing repulsion of the Mo-based (d, pi(x)*)(b) electron pairs versus a favorable but relatively weak electron delocalization. Strongly repelling electron pairs avoid each other, which enforces the twisted geometries and blocks the electron delocalization. Steric hindrance (a nonbonding repulsion of the adjacent Tp(x) ligands and the weak hydrogen-bonding interactions, i.e., OH...ON, OH...OH, and C-H...O((NO/OH))) is shown not to be decisive since neither the removal of the inner 3-Me groups of [Tp(Me)](-) in complex 1' nor the substitution of OH groups by OCH(3) ligands did substantially influence the dihedral twist angle in the minimum energy structure. Yet the relative orientation of the {Mo(NO)}(2+,3+) cores along with the position of the bridging oxygen (significantly bent upon reduction) controls the prospective intramolecular through-bond electron transfer in the mixed valence form. Our DFT modeling demonstrates that a maximum delocalization (via a hole-transfer mechanism) of the unpaired electron in 1'(-), measured as a spin population on the nonreduced Mo2 center, is achieved for the structure with a torsional deflection of 23 degrees, at a cost of 16.5 kcal/mol. These results show that the electron exchange along the Mo-O-Mo array in the originally fully valence-trapped {17e:16e}(-) complexes may be controlled and can be thermally activated (e.g., using a high-boiling solvent or by irradiation at ca. 50-200 cm(-1)).

Synthesis and Characterization of PtRe Alloy Nanoparticles as Electrocatalysts for Methanol Oxidation

We report a new synthesis of PtRe alloy nanoparticles (NPs) and their electrocatalytic activity for methanol oxidation. PtRe alloy NPs with controlled composition were prepared by a capping agents-based colloidal method. In the synthesis, trioctylamine was used as high-boiling solvent, and oleylamine/oleic acid were employed as capping agents to control the particle size and dispersion. The PtRe NPs were fully characterized by TEM, EDX, XRD and XPS. The as-prepared PtRe NPs had a narrow size distribution, and displayed a good dispersion in hydrocarbon solvents. Carbon-supported PtRe catalysts were prepared by physical deposition of as-prepared particles on carbon powder, followed by the catalytic activation at 400 degrees C in Ar/H2. Electrochemical studies showed the PtRe catalysts had high activity for methanol electrooxidation.

Organic Semiconductors for Thermoelectric Applications

The thermoelectric performance of thin films fabricated from two commercially available, highly conductive polymer formulations based on poly (3,4-ethylendioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) was investigated. In order to enhance the electrical conductivity, the high-boiling solvent dimethyl sulfoxide (DMSO) was added. By changing the content of DMSO the electrical conductivity was increased by a factor of two without changing the Seebeck coefficient or the thermal conductivity. We achieved ZT = 9.2 × 10−3 at room temperature upon the addition of 5 vol.% DMSO to the PEDOT:PSS formulation.

Electrochemical Performance of All-Solid-State Lithium Secondary Batteries with Nanosized NiS Active Material Synthesized in High-Boiling Solvent

not Available.

Quality Determination of Nickel-Loaded Silica Prepared from Poaceous Biomass

Klason lignin or preacid hydrolysate of a poaceous biomass such as rice husk, rice straw ( Oryza sativa ), and wheat straw ( Triticum aestivum ) became a good source of highly pure silica by simple calcinations in the testing process for application of high-boiling solvent (HBS) pulping of agricultural byproduct. Especially, Klason lignin or preacid hydrolysis residue of rice husks offered highly purified silica, which was converted to an excellent Ni/SiO(2) catalyst for methanation of carbon dioxide. The Ni/SiO(2) catalyst showed superior properties after the following sequential treatments; preacid hydrolysis of rice husks, HBS pulping of the resultant residue, cellulase hydrolysis of the HBS pulp, calcinations of the resultant powder, impregnation of the silica sample with an aqueous solution of nickel nitrate, and final calcinations.

Optimization of the synthesis of 2-phenyl-1,2,3-triazole

The synthesis of 2-phenyl-1,2,3-triazole by the cyclization of glyoxal phenylosazone in high-boiling solvents in the presence of copper triflate catalyst has been optimized. The structure of the product was confirmed by data of IR, 1H, 13C, and 15N NMR spectroscopy, mass spectrometry, and elemental analysis.

Extraction of Lignin from Carrot Root with High Boiling Solvent

Lignin was extracted from carrot root with high boiling solvent(HBS) 80% ethylene glycol aqueous solution as solvent.Results show that the optimum conditions were as follows:the mass ratio of raw solid materials to solvent was 1∶6,temperature was 210 ℃,reaction time was 2 h,the maximum yield was 17.79%.The chemical structure of the carrot lignin has been characterized by FTIR, UV,and 1H NMR.The chemical composition of HBS lignin from carrot root was determined by elemental analysis,and the content of methoxyl was tested with Viebck′s methods.The C_9 structure of lignin from carrot was estimated as C_9H_9.62O_1.99(OCH_3)_0.96.The elimination efficiency of ·OH free radical by lignin from carrot was studied.The results show that carrot lignin can inhibit the activity of ·OH free radical at low concentrations(50 mg/L)with a maximum inhibition efficiency of 64.9%.

Copper(I) phenoxide complexes in the etherification of aryl halides.

Copper-catalyzed Ullmann ether synthesis has been studied for many years because aryl ethers comprise important classes of medicinally active compounds and agrochemicals.[1,2] The traditional Ullmann-type reactions required high temperatures, use of polar and high-boiling solvents, and stoichiometric quantities of the copper salt. Recently, by combining the copper with a variety of different ligands, milder catalytic Ullmann reactions have been developed [Eq. (1)]. Examples

Silver(I)-Catalyzed Decarboxylation of Aromatic Carboxylic Acids

Known methods of decarboxylation of aromatic carboxylic acids use very high temperatures (170-200 ˚C) and high-boiling solvents like quinoline. This work describes a convenient, widely applicable procedure for silver(I)-catalyzed decarboxylation of various benzoic and heteroaromatic carboxylic acids under relatively mild conditions (DMSO, 120 ˚C).

SnP0.94 active material synthesized in high-boiling solvents for all-solid-state lithium batteries

Tin phosphide (SnP0.94) particles were synthesized by thermal decomposition of tin acetate in a mixed solution of trioctylphosphine and a high-boiling solvent. Teardrop-shaped SnP0.94 particles with the size of about 500 nm were obtained by using trioctylphosphine oxide as a coordinating solvent. In the case using oleylamine as a solvent, the shape of SnP0.94 particles was not uniform. Formation mechanism of teardrop-shaped SnP0.94 was discussed. SnP0.94 particles prepared by using the trioctylphosphine oxide as a coordinating solvent were applied as an active material to all-solid-state lithium cells. The cell Li–In/80Li2S·19P2S5·1P2O5/SnP0.94 exhibited the initial discharge capacity of 1000 mAh g−1 at a current density of 1.3 mA cm−2.