Tetrahydrofuran

About: Tetrahydrofuran is a research topic. Over the lifetime, 11778 publications have been published within this topic receiving 158241 citations. The topic is also known as: diethylene oxide & 1,4-epoxybutane.

Formation of a Cationic Calcium Hydride Cluster with a "Naked" Triphenylsilyl Anion by Hydrogenolysis of Bis(triphenylsilyl)calcium.

Abstract: Protonolysis of bis(triphenylsilyl)calcium [Ca(SiPh3)2(THF)4] (1; THF = tetrahydrofuran) with the NNNN-type macrocyclic amido triamine (Me3TACD)H (TACD = 1,4,7-triazacyclododecane) gave the heteroleptic calcium complex [Ca(Me3TACD)SiPh3] (2) in quantitative yield. Hydrogenolysis of 2 gave the cationic tricalcium dihydride cluster [Ca3H2(Me3TACD)3]+(SiPh3)−·2THF (4a) in high yield with concomitant formation of HSiPh3. In the crystal, 4a consists of a cluster cation and a free triphenylsilyl anion. 1H NMR spectroscopy and deuterium labeling experiments confirmed the selective cleavage of dihydrogen by the highly polar Ca–Si bond in 1.

Air‐Stable, Low‐Toxicity Precursors for CuIn(SeS)2 Solar Cells with 10.1 % Efficiency

Abstract: CuIn(SeS)2 (CISeS) has been regarded as one of the most promising absorber materials for high-efficiency Cu-based thin-film solar cells because of its tunable band gap in the range of 1.0–1.5 eV and high absorption coefficient on the order of 10 cm . However, the highest conversion efficiency to be realized has been only 15.0% for CISe cells as compared to that of 20.3% for Cu(InGa)(SeS)2 cells. [5] The current deposition methods for high-efficiency CISeS cells are mainly based on vacuum methods, that is, co-evaporation or sputtering followed by selenization, which dramatically increase the manufacturing costs owing to the expensive vacuum equipment. Therefore, solution-based nonvacuum deposition methods have been receiving great interest recently because of their low cost and high throughput. Nanoparticle-based ink and molecular precursor-based solutions are two popular routes that are employed to fabricate CISeS solar devices. By using nanoparticle-based methods, conversion efficiencies of 2–8% have been reported for CISeS solar cells. However, the nanoparticlebased method involves complicated synthesis procedures and tedious purification processes. Many issues, such as yield, solubility, long-term stability, and removal of organic ligands etc., still need to be solved. Molecular precursor methods present another promising route, but only a hydrazine-based method has achieved great success, yielding an efficiency beyond 10%. Recently, CISeS cells with an efficiency of 12% have been reported for a hydrazine-based solution method by Mitzi et al., for which this efficiency is comparable to that of cells fabricated by vacuum-based methods. However, hydrazine is a highly toxic and explosive solvent, so mass production is not easy. In this context, seeking a safe precursor-based method utilizing solutions of low toxicity is highly desirable. In this paper, we present a simple and green solution-based processing route for the fabrication of a high-quality CISeS absorber layer. Low-cost Cu2O and In(OH)3 are used as the starting materials and dissolved in butyldithiocarbamic acid that is generated from carbon disulfide and butylamine in situ. By using a spin-casting and annealing process in Se vapor, crack-free and pinhole-free CuIn(SeS)2 thin films were achieved. The most efficient solar cell exhibits a power conversion efficiency (PCE) of 10.1% without antireflection coating. The formation mechanism of the Cu and In precursors is shown schematically in Figure 1a. Butyldithiocarbamic acid was first formed in ethanol from the reaction of carbon disulfide with 1-butylamine at room temperature. As an organic acid, butyldithiocarbamic acid can react with metal oxides or metal hydroxides, such as Cu2O and In(OH)3. [20] The Cu and In precursors were confirmed by FTIR spectroscopy, as shown in Figure S2. It is noteworthy that these molecularbased precursor solutions for Cu and In are highly soluble in ethanol, and a viscous liquid is obtained if all the ethanol is removed under vacuum. More importantly, these sticky precursors can be dissolved in many common organic solvents, including methanol, isopropanol, diethyl ether, toluene, chloroform, chlorobenzene, dimethylformamide (DMF), tetrahydrofuran (THF), and dimethyl sulfoxide (DMSO). In this paper, ethanol was chosen as the solvent for its lack of toxicity. Other small primary and secondary amines, such as ethylamine, propylamine, hexylamine, N-methylhexylamine, diethylamine, dibutylamine, monoethanolamine, and pyrrolidine can also be used to dissolve metal oxides or metal hydroxides. Note that these molecular-precursor solutions for Cu and In remain stable for several months in air and can be directly used to deposit CISeS thin films without additional purification. Note that only volatile CS2, butylamine, and ethanol are used in our system, so that carbon can be completely removed by utilizing a sintering process. The thermogravimetric (TG) profile for the Cu and In precursors is shown in Figure 1b. These Cu and In precursors are thermally stable up to 120 8C, for which the decomposition starts from at approximately 150 8C and ceases at approximately 360 8C. The precursor film was prepared by spin Figure 1. (a) The formation mechanism of Cu and In precursors. (b) Thermogravimetric (TG) analysis of the Cu and In precursors measured under a N2 atmosphere. Inset: the digital photograph of the mixed Cu and In precursors dissolved in ethanol (~0.4m in total metal).

Medium Effects on the Redox Properties of 12-Molybdophosphate and 12-Molybdosilicate

Abstract: The formal redox potentials of 12-molybdophosphate and 12-molybdosilicate up to the twelve-electron reduction per heteropolymolybdate ion were determined by cyclic voltammetry at a glassy carbon electrode in 50% (v/v) water-organic media containing some inorganic acids. These heteropolymolybdates in the presence of 1,4-dioxane (DO) or tetrahydrofuran (THF) display five two-electron reversible cathodic waves, followed by an irreversible two-electron wave, whereas the same heteropolymolybdates in the presence of 1,2-dimethoxyethane, N,N-dimethylformamide, acetonitrile, ethanol, or acetone yield five successive redox couples of 2,2,2,4, and 2e− (electrons) each. The eight-electron reduction species of 12-heteropolymolybdates are stabilized by cyclic ethers such as DO or THF. The stabilization of the eight-electron reduction species by the addition of a cyclic ether has been explained by taking into account the adduct formation between the molecules of the cyclic ether and 12-heteropolymolybdate.

Reduction of carbodiimides by samarium(II) bis(trimethylsilyl)amides-formation of oxalamidinates and amidinates through C-C coupling or C-H activation.

Abstract: The reaction of [Sm{N(SiMe3)2}2(THF)2] (THF = tetrahydrofuran) with carbodiimides RNCNR (R = Cy, C6H3-2,6-iPr2) led to the formation of dinuclear SmIII complexes via differing C−C coupling processe...