ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTPalladium-catalyzed cross-coupling reaction of homoallylic or homopropargylic organozincs with alkenyl halides as a new selective route to 1,5-dienes and 1,5-enynesEiichi Negishi, Louis F. Valente, Makoto KobayashiCite this: J. Am. Chem. Soc. 1980, 102, 9, 3298–3299Publication Date (Print):April 1, 1980Publication History Published online1 May 2002Published inissue 1 April...

The morphology-controlled synthesis and near-infrared (NIR) absorption properties of W(18)O(49) were systematically investigated for the application innovative energy-saving windows. Various morphologies W(18)O(49), such as nanorods, nanofibers, nanograins, nanoassembles, nanoplates, nanoparticles, with various sizes successfully synthesized by solvothermal reactions using organic alcohols reaction media WCl(6), W(EtO)(6), WO(3) solids tungsten source. nanorods less than 50 nm in length...

Abstract We report a new dicalcium silicate phosphor, Ca 2− x Eu SiO 4 , which emits red light in response to blue‐light excitation. When excited at 450 nm, deep‐red emission 650 nm was clearly observed 1.2 0.8 the external and internal quantum efficiencies of were 44 % 50 %, respectively. The from strongly related peculiar coordination environments 2+ two types sites. red‐emitting 2 :Eu phosphors are promising materials for next‐generation, white‐light‐emitting diode applications.

A complex pattern: Single-phase brookite, rutile, and rutile–anatase nanoparticles can be prepared from the new water-soluble titanium(IV) (NH4)6[Ti4(C2H2O3)4(C2H3O3)2(O2)4O2]⋅4 H2O. It appears that structural similarity of anion to brookite architecture allows directional synthesis nanopowders in a pure form (see scheme).

Full details of an anti-selective catalytic asymmetric nitroaldol reaction promoted by a heterobimetallic catalyst comprised Nd5O(OiPr)13, amide-based ligand, and NaHMDS (sodium hexamethyldisilazide) are described. A systematic synthesis evaluation ligands led to the identification optimum ligand 1m, which provided suitable platform for Nd/Na complex. During preparation in THF, heterogeneous mixture developed centrifugation suspension allowed separation precipitate, contained active could be...

Abstract The growing significance of nanocrystalline inorganic functional materials in the fields catalysis, electronics, and energy conversion together with increasing demand society for safer, softer, “greener” technologies has drawn considerable attention researchers toward water-based solution processes synthesis such materials. In this respect complex oxides, containing d0-transition metals, as Ti, Nb, Ta, or Si represent an outstanding challenge chemists due to extremely narrow range...

Phosphors with sufficient red emission component are necessary for warm white light-emitting diodes. In this work on (Sr,Ba)2(1–x)Eu2xSiO4 phosphors, (Sr,Ba)1.5Eu0.5SiO4 achieved 75% of an internal quantum efficiency under excitation by blue light. Surprisingly, the exhibited orange emission, against well-known traditional green-yellow (Sr,Ba)2SiO4:Eu2+. Moreover, concentration quenching Eu2+ in (Sr,Ba)2SiO4 was abnormally unobvious. With help calculations based density functional theory, it...

We report the first successful synthesis of TiO2(B) nanoparticles by a one-step hydrothermal process. The process was performed under acidic conditions in 0.59 M H2SO4 solution at 160 °C for 24 h or 200 6 using titanium metal complex with glycolic acid. prepared were characterized XRD, Raman spectroscopy, and TEM. is metastable phase one most intriguing forms oxide. All methods reported to date have required multistep involving solid-state an alkali titanate, ion-exchange reaction, gentle...

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTA palladium-catalyzed stereospecific substitution reaction of homoallylzincs with .beta.-bromo-substituted .alpha.,.beta.-unsaturated carbonyl derivatives. A highly selective synthesis mokupalideMakoto Kobayashi and Eiichi NegishiCite this: J. Org. Chem. 1980, 45, 25, 5223–5225Publication Date (Print):December 1, 1980Publication History Published online1 May 2002Published inissue 1 December...

Specific heat, susceptibility, and magnetization measurements were performed on a random mixture of two antiferromagnets with competing spin anisotropies, Fe${\mathrm{Cl}}_{2}$\ifmmode\cdot\else\textperiodcentered\fi{}2${\mathrm{H}}_{2}$O Co${\mathrm{Cl}}_{2}$\ifmmode\cdot\else\textperiodcentered\fi{}2${\mathrm{H}}_{2}$O. From these experiments, the concentration versus temperature phase diagram is obtained, which shows clearly existence tetracritical point. The compared those obtained by...

Flux treatment using various molten salts was performed for SrTiO3 powders. Morphology of crystals obtained by the flux strongly depended on kinds used. Large cubic exposing {100} facets with a size 5–6 μm were LiCl whereas truncated cubes and {110} 200–400 nm when NaCl or SrCl2 used as reagent. In contrast, KCl gave characteristic shaped 300 nm. Electron microscope observation electron diffraction analysis revealed that treated expose {100}, {120}, {121} facets. exhibited higher activity 20...

It has been found that Mn4+-activated La2MTiO6 (M = Mg and Zn) functions as novel Eu-free phosphors for red emission in this work. La2MTiO6:Mn4+ exhibited with a peak at 710 nm under excit...

Dielectric capacitors have greater power densities than batteries, and, unlike they do not utilize chemical reactions during cycling. Thus, can become ideal, safe energy storage devices. However, dielectric yield rather low compared with other devices such as batteries and supercapacitors. Here, we present a rational approach for designing ultrahigh using two-dimensional (2D) high-κ perovskites (Ca2Nam–3NbmO3m+1; m = 3–6). Individual Ca2Nam–3NbmO3m+1 nanosheets exhibit an strength (638–1195...

As a member of the 2D materials family, metal nanosheets (metallenes) have received increasing attention due to their intriguing properties distinct from those graphene and other inorganic nanosheets. However, synthesis metallenes is still challenging, owing lack an efficient synthetic approach. Here we present facile one-pot approach controlled Pd A key feature this process stepwise reaction using 2,4,6-trichlorophenyl formate (TCPF); TCPF emits carbon monoxide gas, which acts as both...

Abstract Copolymerization of carbon dioxide with epoxypropane (propylene oxide) in the presence a diethylzinc/dihydric phenol system was examined. A spectroscopic study copolymer revealed that one aromatic group introduced chain. The osmometric number average molecular weight agrees deduced from studies. introduction into chain takes place at initiation step copolymerization, and catalytic activities diethylzinc/phenol systems depend on or absence ZnOXOZn group, where X may be phenylene,...

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTDiethylzinc-Dihydric Phenol System as Catalyst for the Copolymerization of Carbon Dioxide with Propylene OxideMakoto Kobayashi, Shohei Inoue, and Teiji TsurutaCite this: Macromolecules 1971, 4, 5, 658–659Publication Date (Print):September 1, 1971Publication History Published online1 May 2002Published inissue 1 September 1971https://pubs.acs.org/doi/10.1021/ma60023a033https://doi.org/10.1021/ma60023a033research-articleACS PublicationsRequest reuse...

Abstract Copolymerization of carbon dioxide (CO 2 ) and propylene oxide (PO) was carried out by using diethylzinc/water diethylzinc/methanol catalyst systems. A remarkable amount polycarbonate obtained the former system, but hardly any polymer formed with latter catalyst. The difference between these two systems examined in relation to elementary processes copolymerization. Both catalysts react CO produce XZnOCOOR, where X = OCH 3 for system (OZn) n OH or C H 5 system. reactivity XZnOCOOR PO...

A series of oxynitride solid solutions, NaxLa1−xTaO1+2xN2−2x with x = 0.1, 0.2, 0.25, 0.3, 0.5, 0.75 and 0.85, was successfully synthesized by nitridation amorphous oxide precursors under an NH3 stream at 1273 K. The band gaps the solutions increased Na content. Photoelectrochemical analysis conducted to obtain information on potentials solutions. valence maxima were more positive than that LaTaON2 (x 0). Solid 0.20–0.85 exhibited photocatalytic activity for both H2 O2 evolution visible...

Abstract Mechanical exfoliation of layered materials is one the most effective methods for obtaining two-dimensional (2D) nanosheets. However, this approach still limited to van der Waals (vdW) materials, where interlayer interactions are governed by weak vdW forces. In study, we used a perovskite ferroelectric (CsPb2Nb3O10) as model system explore mechanical behavior ionically bonded non-vdW materials. Due relatively out-of-plane bonds involving Cs⁺ ions, CsPb2Nb3O10 could be cleaved into...

Water splitting under visible light irradiation using a Z‐scheme system combining nonmetal oxides of TaON and (CuGa) 0.5 ZnS 2 is demonstrated. The key factors lie in coloading with Ir CoO x cocatalysts on reduced graphene oxide (RGO) as solid‐state electron mediator. loaded by an impregnation method, while either or photodeposition methods. Loaded boosts the migration from to RGO, works active site for O evolution. Photocatalytic reduction RGO accompanied simultaneous oxidation Co 2+ ions...

Heat accumulation and spring freeze, both strongly influenced by snow cover, are key factors regulating the onset of phenology. In forest ecosystems, decreased cover due to climate change may differently impact heat occurrence freezes between canopy gap under tree canopy, leading varied phenological responses. this study, we examined how phenology seedling responds across microsites explored whether these responses species-specific. We conducted a manipulation experiment in planted northern...