溴化四苯基膦合成的研究

研究了以三苯基膦和溴苯为原料用NiCl2为催化剂定向合成溴化四苯基膦的原子经济性绿色合成反应,系统的考察了催化反应过程中催化剂、反应温度、溶剂、反应时间等因素对产物收率的影响,同时敢讨论了催化剂回收和产物提纯的工艺条件,优化结果表明采用无毒害正辛醇溶剂,回流温度为195℃,反应6h,产物收率可达89%以上。在产物收率和有利环境友好方面的结果尚未见文献报道。     

Synthesis and structure of tetra-para-tolylantimony bromide

Reaction of penta-para-tolylantimony with tri-para-tolylantimony dibromide resulted in tetra-para-tolylantimony bromide in 97% yield. The structure of the obtained compound was proved by X-ray diffraction analysis.     

Synthesis and transformations of triphenylpropargylphosphonium bromide

A method of the synthesis of triphenylpropargylphosphonium bromide is developed. Its isomerization and hydration in various solvents are studied, and reactions with secondary amines, triethylamine, and triphenylphosphine are carried out. It is established that secondary amines add to the intermediate allene isomer with subsequent migration of the formed double bond to the phosphorus atom. The reaction of triethylamine with triphenylpropargyl and triphenylethynyl bromides occurs similarly to alkaline hydrolysis involving attack of the amine on the phosphorus atom. Triphenylphosphine forms with triphenylpropargylphosphonium bromide a bis-salt with a terminal methylene group. Experimental evidence is obtained showing that for phosphoxazole derivatives to form from oximes derived from triphenyl(oxomethyl)phosphonium salts that latter should bear an aryl substituent at the keto group.     

Synthesis and reactions of perfluoro-n-octylmagnesium bromide

Perfluoro-n-octylmagnesium bromide has been conveniently synthesized through the metal-halogen exchange reaction between perfluoro-n-octyl iodide and ethyl- or phenyl-magnesium bromide. The thermal stability of the Grignard reagent and the products of the thermal decomposition have been estimated in diethyl ether and tetrahydrofuran. Reactions of the Grignard reagent with various substrates such as water, acetone, hexafluoroacetone, trimethylchlorosilane and carbon dioxide indicate the synthetic utility of n-octylmagnesium bromide.     

Synthesis of trifluoromethyltriazoles from trifluoroacetohydrazonoyl bromide

N-Phenyltrifluoroacetohydrazonoyl bromide ( 1 ) reacted with potassium isothiocyanate and isocyanate to give 5-imino-4-phenyl-2-trifluoromethyl-δ²-1,3,4-thiadiazoline and 1-phenyl-3-trifluoromethyl-δ²-1,2,4-triazolin-5-one, respectively. On treatment with several types of cumulative double bonds such as alkyl isothiocyanate, isocyanate, and carbodiimide, 1 afforded regioselectively the corresponding trifluoromethylthiadiazoline, -oxadiazoline, and -triazoline, respectively. These cycloadducts were assumed to form through the stepwise path involving the addition of 1 toward the cumulative double bond followed by the intramolecular cyclization. Concerning cyanamides, the corresponding triazoles were obtained and the reactions with pyridines afforded the triazolopyridinium bromides. The reactivity of the latter was found to depend on the substituents on the pyridine nucleus.     

Synthesis and polymerization of N,N-diallylpyrrolidinium bromide

The synthesis of N,N-diallylpyrrolidinium bromide (DAPB) and its free-radical initiated polymerization are described. It is shown that DAPB polymerizes via a cyclopolymerization mechanism leading to a polyelectrolyte consisting of azoniaspiro[4.4]-nonane containing repeating units.     

Synthesis and properties of lead-free formamidinium bismuth bromide perovskites

In the past few years, Pb-free metal halide perovskites have been recognized as a promising material for various optoelectronic applications because of some of their unique features, such as direct and tunable bandgap, visible light emission, narrow emission spectra, lower toxicity level, and easy solution processability. Recently, several Bi-based perovskite-like single crystals (SCs) and nanocrystals (NCs) were reported, which are mostly suffering from their poor structural stability and lower emission intensity. Here, we report the growth of millimeter-sized formamidinium bismuth bromide (FA₃Bi₂Br₉) perovskite SCs via slow solvent evaporation method. They crystallized into a trigonal crystal structure and exhibit an indirect bandgap of 2.71 eV. These results are supported by the first-principle density-functional theory studies. We have also synthesized nanometer-sized spherical blue-emitting FA₃Bi₂Br₉ NCs by solvent ligand-assisted reprecipitation method and achieved a maximum photoluminescence quantum yield of 22%. We observe that the addition of excess ligands into the FA₃Bi₂Br₉ NCs solution before the purification step significantly improves the optical and colloidal stability of the NCs.     

Reaction of indolylmagnesium bromide and chloromethylpyridines. Synthesis of skatylpyridines and piperidines

The reaction of indolylmagnesium bromide with the 2-, 3-, and 4-chloromethyl-pyridines is reported. Methods are described for the preparation of 2-, 3- and 4-skatylpyridine and 2-, 3- and 4-skatylpiperidine.     

Synthesis of dimeric pyridinium bromide under silica supported approach

Abstract

Synthesis of dimeric substituted ester derivative of pyridinium salt with flexible linker units under conventional/silica supported approach. Solid-phase approach is much superior to the conventional method due to nontoxic, solvent free, easy work up procedure, and lesser reaction period. Synthesized dimeric ester derivative of pyridinium salts is showed excellent catalytic response for the preparation of oxizinone derivatives under conventional/approach.     

Synthesis and aqueous reactivity of n-adamantylidylcarbinyl-n,n-dimethyl-4-cyanoanilinium bromide

The aqueous decomposition of the title allyl compound, whose synthesis is also described, is strongly indicative of concurrent S_N1 and S_N2 reactivity.     

Synthesis and structures of a 3-sila-beta-diketiminatomagnesium bromide, ketenimide and triflate

The crystalline compounds [Mg(Br)(L)(thf)].0.5Et2O [L = {N(R)C(C6H3Me2-2,6)}2SiR, R = SiMe3] (1), [Mg(L){N=C=C(C(Me)=CH)2CH2}(D)2] [D = NCC6H3Me2-2,6 (2), thf (3)] and [{Mg(L)}2{mu-OSO(CF3)O-[mu}2] (4) were prepared from (a) Si(Br)(R){C(C6H3Me2-2,6)=NR}2 and Mg for (1), (b) [Mg(SiR3)2(thf)2] and 2,6-Me2C6H3CN (5 mol for (2), 3 mol for (3)), and (c) (2) + Me3SiOS(O)2CF3 for (4); a coproduct from (c) is believed to have been the trimethylsilyl ketenimide Me3SiN=C=C{C(Me)=CH}2CH2 (5).     

Synthesis of arenerhenium tricarbonyl cations and thermal transformations of rhenium pentacarbonyl bromide

Conclusions The addition of [BrRe(CO)₄]₂, which supposedly is a source of the Re(CO)₅ ⁺ cation, strongly accelerates the reaction between BrRe(CO)₅ (I) and mesitylene in either nonane or octane, which leads to [(Mes)Re(CO)₃]⁺[(CO)₆Re₂Br₃]^–. A new rhenium carbonyl bromide, apparently of the cluster type, was obtained when (I) is refluxed in nonane.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 3, pp. 709–710, March, 1982.     

溴化苄基取代吡啶类季铵盐的制备和抗菌性能

抗菌材料和抗菌制品的研究与应用一直是世界各国研究的重要课题~([1-3]),其中有机抗菌剂占据主要地位.季铵盐是研究比较多的一类有机抗菌剂,它们表现出良好的物理性质,如胶束浓度低,黏弹性好和溶解性强~([4]),同时此类抗菌剂具有强效的抗菌作用~([5]),引起了人们的极大兴趣.季铵盐广泛应用于医药、卫生、食品、饲料工业、农业、纺织、塑料、橡胶、造纸、水处理、油田开采、涂料、日常生活等多种领域~([6-10]).     

十六烷基三甲基溴化铵催化合成间甲苯氧乙酸

<正>植物生长调节剂系人工合成具有天然植物激素活性的物质。芳氧乙酸及其酯类是一种具有多种用途的选择性除莠剂,同时也是植物的生长调节剂和除草剂[1]。研究探讨合成芳氧乙酸的新技术以提高生产能力,对工农业生产有着重要的现实意义。制备芳氧乙酸一般采用Williamson法、     

Surface and volume properties of dodecylethyldimethylammonium bromide and benzyldimethyldodecylammonium bromide: II. Volumetric properties of dodecylethyldimethylammonium bromide and benzyldimethyldodecylammonium bromide

Density measurements were carried out for aqueous solutions of two cationic surfactants: dodecylethyldimethylammonium bromide (C₁₂(EDMAB)) and benzyldimethyldodecylammonium bromide (BDDAB). On the basis of the obtained results of the measurements the CMC and partial molar volumes of the surfactants studied were also determined. The obtained CMC values were also analyzed with those accounted on the basis of the surface tension data from the previous paper [J. Harkot, B. Jańczuk, J. Colloid Interface Sci. (2008), submitted for publication]. The values of CMC determined from the surface tension and density measurements for C₁₂(EDMAB) are equal to 9.9×10⁻³ and 1.5×10⁻² M and for BDDAB to 5.25×10⁻³ and 5.3×10⁻³ M, respectively. These obtained values are very similar. However, in the literature it is difficult to find the CMC values for C₁₂(EDMAB) and BDDAB determined by these two methods used by us—especially from the density measurements for BDDAB and surface tension measurements for C₁₂(EDMAB). In the case of the apparent molar volumes of C₁₂(EDMAB) there is a good agreement between the values obtained by us and those found in the literature. The CMC values for C₁₂(EDMAB) and BDDAB were also determined on the basis of their surface tension and free energy of electrostatic interactions between the polar heads of these surfactants and compared with those obtained from the surface tension and density measurements. It was found that the theoretically obtained CMC values were close to those determined from the density and surface tension data for the C₁₂(EDMAB) and that the ratios of the CMC values of the surfactants to their concentration at which the water surface tension decreased by about 20 mN/m proved that the presence of the aryl group in the BDDAB head instead of the methyl group caused that its micellization process was more inhibited in relation to its adsorption at air–water interface than that of C₁₂(EDMAB).     

Interaction between lead bromide and barium bromide

The phase diagram of the PbBr₂-BaBr₂ system over the entire concentration range is studied for the first time by differential thermal analysis and X-ray powder diffraction analysis. No new compounds are formed in the system. The phase diagram is represented by a continuous series of solid solutions (type I by Rooseboom’s classification). The unit cell parameters change as a linear function of composition.     

Synthesis of ordered spiral and ring-like polypyrrole nanowires in cetyltrimethylammounium bromide crystalline suspension

Spiral dislocation morphology on the surface of cetyltrimethylammounium bromide (CTAB) crystallites has been discovered for the first time. By addition of ammonium peroxydisulfate into CTAB crystalline suspension, a drastic change in the morphology of result crystallites is observed from spiral to two dimensional (2D) islands. The spiral and 2D-island structures of these crystallites could be use as the templates for the synthesis of spiral and ring-like polypyrrole (PPy) nanowires, respectively, via direct chemical oxidative polymerization of pyrrole due to the oxidation reaction occurring preferentially at the steps of these crystallites. The mechanism of adsorption of pyrrole oligomers on the steps of these crystallites is proposed for the growth of PPy spiral and ring-like nanowires.