共查询到20条相似文献,搜索用时 10 毫秒
1.
Sakae Uemura Shin-ichi Fukuzawa Akio Toshimitsu Masaya Okano 《Tetrahedron letters》1982,23(11):1177-1180
Treatment of olefins with phenyltellurium(I) or (IV) species [(PhTe)2, PhTeCN, PhTeBr3] in alcohol at room to reflux temperature for 1–24 h produces the corresponding (2-alkoxyalkyl)phenyltellurium dihalides in good yields, the reaction being trans-stereoselective and highly regioselective. 相似文献
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Yamada M Watanabe S Hoshino O Ishizaki M Hayashida M Tanaka A Hara H 《Chemical & pharmaceutical bulletin》2003,51(10):1220-1221
Allyl aryl ethers can be easily cleaved by the use of 10% Pd/C under the mild and basic conditions. 相似文献
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Pastine SJ Okawa D Kessler B Rolandi M Llorente M Zettl A Fréchet JM 《Journal of the American Chemical Society》2008,130(13):4238-4239
A facile patterning method for the functionalization of vertically aligned carbon nanotubes is described. Modification of the surface of nanotube forests with hydrophilic, hydrophobic, or polymerizable small molecules was achieved via UV-triggered attachment of perfluoroarylazides. Multiple functionalizations of the tube surface can be achieved. Macro- and micropatterning of forest substrates were demonstrated. Superhydrophobic surfaces containing superhydrophilic regions were prepared. 相似文献
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Sung Hoon Kim Kyongtae Kim Jaheon Kim Kimoon Kim Jung-Hyup Kim 《Journal of heterocyclic chemistry》1993,30(4):929-938
The reactions of 2-alkyl-5-phenylisothiazole-3-thiones with 2-chloro-1,3-dicarbonyl compounds in chloroform gave the corresponding isothiazolium chlorides which, upon treatment at room temperature with sodium borohydride in a mixture of chloroform and ethanol, underwent S? N bond cleavage to give 3-alkyl-4,5-disubstituted-2-thiophenacylidenethiazolines. Similarly, treatment of the isothiazolium chlorides with triphenylphosphite in chloroform at 60° afforded the same thiazoline derivatives. 相似文献
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We report a facile chemical route for the synthesis of monodisperse nanocrystals of various metal sulfides (PbS, Cu(2)S, and Ag(2)S) and their assemblies into nanocrystal superlattices (NCSs); the sulfides NCSs were precipitated by adding ethanol to nanocrystal colloids, which were obtained directly by a reaction between metal thiolate and thioacetamide in a pure dodecanethiol solvent. 相似文献
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In this paper, we demonstrate a simple and general "dispersion-decomposition" approach to the synthesis of metal sulfide nanocrystals with the assistance of alkylthiol. This is a direct heating process without precursor injection. By using inorganic metal salts and alkylthiol as the raw materials, high-quality Ag(2)S, Cu(2)S, PbS, Ni(3)S(4), CdS, and ZnS nanocrystals were successfully synthesized. The mechanism study shows that the reaction undergoes two steps. A key intermediate compound, metal thiolate, is generated first. It melts and disperses into the solvent at a relatively low temperature, and then it decomposes into metal sulfide as a single precursor upon heating. This method avoids using toxic phosphine agent and injection during the reaction process. The size and shape of the nanocrystal can be also controlled by the concentration of the reactant and ligands. Furthermore, the optical properties and assembly of the nanocrystals have also been studied. This report provides a facile, direct-heating "dispersion-decomposition" approach to synthesize metal sulfides nanocrystals that has potential for future large-scale synthesis. 相似文献
8.
β-In2S3 superstructure comprised of nanoflakes with the sizes of 200–450 nm has been synthesized by a facile reflux method with the assistance of the sodium dodecylsulfate at low temperature (80 °C). XRD, SEM, TEM, HRTEM, and UV–vis spectra were used to characterize the In2S3 superstructure. Prepared In2S3 superstructures exhibited high photocatalytic activities in the degradation of rhodamine B under visible light irradiation (λ > 420 nm), in which 97.5% RhB was photodegraded after 60 min. 相似文献
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Xu Su Gang Zhang Tao Liu Ying Liu Jingui Qin Changtian Chen 《Russian Journal of Inorganic Chemistry》2006,51(12):1864-1868
Pure BiSI (bismuth sulfide iodide) crystals were synthesized directly from the reaction of BiCl3, (NH2)2CS, and I2 through a mild hydrothermal process (160°C for 30 h) after simple filtration and washing. The as-prepared crystals were characterized
by XRD, IR, XPS, and SEM. The band gap of the product was calculated to be about 1.8 eV from UV-Vis-NIR results. A possible
reaction mechanism was proposed.
This article was submitted by the authors in English. 相似文献
11.
A one pot, high yield synthesis of depsipeptides is described involving room temperature condensation of hindered substrates (N-Boc amino acids and benzyl α-hydroxy esters) in the presence of DCC and a dialkylaminopyridine. In this manner previously inaccessible depsipeptides were prepared. 相似文献
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Treatment of N-(o-alkynylphenyl)imine derivatives with W(CO)(5)(L) induces the 5-endo-mode of cyclization of the imine nitrogen onto the electrophilically activated alkyne moiety to afford a novel reactive species, a metal-containing azomethine ylide. [3 + 2] cycloaddition of this ylide species with various electron-rich alkenes proceeds smoothly to give unstable carbene complexes, which in turn undergo 1,2-hydrogen-, alkyl-, and aryl-migration to afford in good yield 6-5-5 tricyclic indole skeletons having an alkyl or an aryl substituent at the 3-position of the indole nucleus. 相似文献
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A novel environment-friendly system is proposed tofabricate polymer brush, which has the advantages including non-toxic and inexpensive initiator(eosin Y), visible-light exposure(λ= 515 nm), water medium and ambient environment. The experimental results from UV-Vis spectroscopy, AFM-based single molecule force spectroscopy(SMFS) and other measurements indicate thata polymer brush with a living nature is fabricated via free radical polymerization. This polymer brush may find applications incoatings, bio-interfaces and so forth. 相似文献
16.
Jeyaprakash JD Samuel S Rühe J 《Langmuir : the ACS journal of surfaces and colloids》2004,20(23):10080-10085
We describe a simple photochemical process which allows fluoropolymers to be chemically bound at room temperature onto SiO2 surfaces. To achieve this, at first a benzophenone silane is used to form a self-assembled monolayer on the surface of the substrate, which is subsequently coated with the fluoropolymer and irradiated with UV light of wavelength 365 nm. Using this very simple approach, we have been able to create ultrahydrophobic surfaces with very low surface free energies together with a good degree of control in thickness and composition as well as strong adhesion to the monolayer. The use of a UV-based process to attach the films on SiO2 surfaces opens the door for photopatterning of surfaces with fluorinated and nonfluorinated compounds to yield well-defined microstructures with spatial control of the wetting properties of the substrates. 相似文献
17.
Here we demonstrate a facile strategy of preparing gold nanoparticle (AuNP) and DNA conjugates by in situ generation of strong metal affinity capping ligands, dithiocarbamates (DTC) modified oligonucleotides; the conjugates produced are stable at elevated temperature, resistant to ligand displacement and preserve the functionality of the conjugated oligonucleotides. 相似文献
18.
《Journal of fluorine chemistry》1988,39(1):87-98
In the presence of tetrakis(triphenylphosphine)nickel, fluoroalkylation reactions of aniline and its derivatives occur under mild conditions, giving good yields of the corresponding o- and p-fluoroalkylaniline. The reaction shows regioselectivity. The hydrolytic behaviors of the products are also described. 相似文献
19.
Kinetics and concentration profile associated with the regulated radiodegradation of bilirubin in an organic solvent were
assessed. The pure unconjugated specimen was prepared in chloroform (40.0 μM). The depletion of bilirubin was almost linear
with dose, and complete degradation was accomplished with doses in excess of 100 Gy. The method was also evaluated for the
explicit production of the long-wavelength isomer of biliverdin, which was characterized spectrometrically by an absorbance
band in the region 600–650 nm. Results including differences in air, N2 and O2 purged samples are presented to identify the atmospheric medium for optimum production of biliverdin. The process was regulated
by controlling the dose. The general rate constant of the depletion process was estimated at a dose rate of 5.67·10−2Gy·s−1. The method is a convenient substitute for light illumination studies of bilirubin.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
20.
A rapid and sensitive spectrophotometric method is described for the determination of trace amounts of selenium using Variamine Blue (VB) as a chromogenic reagent. The proposed method is based on the reaction of selenium with potassium iodide in an acidic medium to liberate iodine, which oxidizes Variamine Blue to form a violet-colored species having an absorption maximum at 546 nm. Beer's law is obeyed in the range 2-20 g of selenium in a final volume of 10 ml. The molar absorptivity and Sandell's sensitivity were found to be 2.6 x 10(4) l mol-1 cm-1 and 0.003 microgram cm-2, respectively. The optimum reaction conditions and other analytical parameters were evaluated. The effect of interfering ions on the determination is described. The proposed method has been successfully applied to the determination of selenium in real samples of water, soil, plant materials, human hair, and synthetic samples of cosmetics and pharmaceutical preparations. 相似文献