结晶态SO_4~(2-)/ZrO_2-SiO_2超强酸催化剂的制备及性能测定

采用一种沉淀／混合沉淀的方法, 制得了具有类似于分子筛结构的结晶型二元氧化物 Ｚｒ Ｏ２ Ｓｉ Ｏ２． 用１ ｍ ｏｌ／ｄｍ ３ 的硫酸处理该氧化物并在５５０ ℃焙烧, 制得了具有类似于分子筛结构的结晶态超强酸催化剂 Ｓ Ｏ４２－ ／ Ｚｒ Ｏ２  Ｓｉ Ｏ２． 采用 Ｘ Ｒ Ｄ、 Ｉ Ｒ、 Ｔ Ｇ、 Ｓ Ｅ Ｍ 等对催化剂的结构进行了表征, 发现该催化剂的 Ｘ Ｒ Ｄ谱图与 Ｚ Ｓ Ｍ５ 分子筛的 Ｘ Ｒ Ｄ谱图非常类似． 用指示剂法证实了催化剂的超强酸性． 还考察了催化剂对于乙酸／丁醇酯化反应的催化活性．     

对甲烷氧化偶联W—Mn／SiO2催化剂Na2WO4的流失及其影响的考察

用ＸＲＤ，ＦＴ－ＩＲ，ＥＳＲ，Ｈ２－ＴＰＲ和ＴＯＰ等方法，对Ｎａ２ＷＯ４Ｍｎ２Ｏ３／ＳｉＯ２催化剂和其经水煮处理的一系列样品进行一表征。实验发现该催化剂中的结晶态ＮａＷＯ４易于流失，单层分布的Ｎａ２ＷＯ４在苛刻的处理条件下也有可能流失。     

稀土溴化物与甘氨酸配合物标准摩尔生成焓的测定

采用量热法在２９８１５±０１０Ｋ测量了ＲＥＢｒ３·３Ｇｌｙ·３Ｈ２Ｏ（ＲＥ＝Ｌａ、Ｃｅ、Ｐｒ、Ｎｄ、Ｓｍ、Ｅｕ、Ｇｄ、Ｔｂ、Ｄｙ、Ｙ；Ｇｌｙ为甘氨酸）和甘氨酸在水中的积分溶解热，及ＲＥＢｒ３·ｎＨ２Ｏ（ＲＥ＝Ｌａ、Ｃｅ、Ｐｒ时，ｎ＝７；ＲＥ＝Ｎｄ、Ｓｍ、Ｅｕ、Ｇｄ、Ｔｂ、Ｄｙ、Ｙ时，ｎ＝６）在甘氨酸水溶液中的积分溶解热。用本研究设计的热化学循环求得上述１０种ＲＥＢｒ３·３Ｇｌｙ·３Ｈ２Ｏ配合物的标准摩尔生成焓，并计算出它们的晶格能。     

水面石油污染物的光催化降解

制备了漂浮负载型ＴｉＯ２光催化剂,并用ＸＲＤ,ＢＥＴ,ＴＥＭ和ＳＥＭ等方法进行了表征。研究了这类催化剂对水面石油污染物的光催化降解,实验结果表明,掺杂Ｆｅ＾３＋的ＴｉＯ２光催化剂具有高的光催化活性,经高压汞灯照射８ｈ,水面原油降解７５％。     

Ce2O—TiO2／SiO2的制备及除氟性能研究

以ＳｉＯ２为基质，ＣｅＯ２ＴｉＯ２为包覆物质，采用溶胶凝胶法制备ＣｅＯ２ＴｉＯ２／ＳｉＯ２表面复合物，并对所制复合物进行除氟测试。用扫描电镜（ＳＥＭ）观察表面形貌，讨论实验环境、试剂用量等因素对ＣｅＯ２ＴｉＯ２／ＳｉＯ２制备及除氟性能的影响，结果表明：ｎＴｉ（ＯＣ４Ｈ９）４／ｎＣｅＣｌ３·７Ｈ２Ｏ＝１、ｎＣＨ３ＣＯＯＨ／ｎＴｉ（ＯＣ４Ｈ９）４＝４５、ｎＣ３Ｈ８Ｏ３／ｎＴｉ（Ｏ４Ｈ９）４＝０３、ＲＨ＝９５％，热处理温度１１０℃时，所制ＣｅＯ２ＴｉＯ２／ＳｉＯ２对Ｆ－的吸附容量（ｑ）为２１４ｍｇ／ｇ，去除率（Ｅ）为８５６％。     

LaCaMnO3催化剂活性相的结构和形成机理的研究

利用ＴＧ，ＤＴＡ，ＸＲＤ和ＸＰＳ方法研究了Ｌａ０．２Ｃａ０．８ＭｎＯ３催化剂的结构和形成机理。样品用Ｌａ，Ｃａ，Ｍｎ混合硝酸盐制备。随着焙烧温度的升高发生的一系列的固相反应，发现氨氧化催化剂催化活性与生成的ＣａＭｎＯ３含量成正比。在９００℃制备的含有ＣａＭｎＯ３，Ｌａ０．５７５Ｃａ０．４２５ＭｎＯ３，Ｍｎ２Ｏ３和Ｌａ２Ｏ３的混合物是氨氧化最佳催化剂，活性相是ＣａＭｎＯ３，并具有大量的氧空穴。     

结晶态SO^2—4／ZrO—SiO2超强酸催化剂的制备及性能测定

采用一种沉淀／混合沉淀的方法,制得了具有类似于分子筛结构的结晶二元二氧化物ＺｒＯ２－ＳｉＯ２。用１ｍｏｌ／ｄｍ＾３的硫酸处理经物并在５５０℃焙烧,制得了具有类似于分子筛结构的结晶态超强酸催化剂ＳＯ＾２－４／ＺｒＯ２－ＳｉＯ２。采用ＸＲＤ,ＩＲ,ＴＧ,ＳＥＭ等对催化剂的结构进行了表征,发现该催化剂的ＸＲＤ谱图与ＺＳＭ－５分子筛的ＸＲＤ谱图非常类似,用指示剂法证实了催化剂的超强酸性。还考察了催化剂对于     

超细纳米TiO2/Al2O3复合体的制备及其组成分布的研究

采用溶胶－凝胶法成功制备出纳米尺寸的ＴｉＯ２／Ａｌ２Ｏ３复合体,并用ＸＲＤ、ＸＰＳ和ＩＲ等手段研究了复合体的结构组成及ＴｉＯ２和Ａｌ２Ｏ２的分布状态,进一步探讨了机械研磨法制备ＴｉＯ２／Ａｌ２Ｏ３复合体等因素对其组成的影响。ＸＲＤ分析表明,在〔Ａｌ＾＋３〕：〔Ｔｉ＾＋３〕＝１：１（或０．５）情况下,改进的溶胶－凝胶法制备纳米ＴｉＯ２／Ａｌ２Ｏ３复合体,其ＴｉＯ２主要分布在Ａｌ２Ｏ３的表面层,在含Ｔ     

在（TPA）2O—Na2O—SiO2—H2O体系中MFI型硅沸石的结晶行为（Ⅱ）

以白炭黑和硅溶胶为硅源，在（ＴＰＡ）２Ｏ－Ｎａ２Ｏ－ＳｉＯ２－Ｈ２Ｏ体系６０℃下合成了高结晶度纯相硅沸石，由ＳＥＭ没得其晶粒尺寸为０．２μｍ和０．４５μｍ用ＸＲＤ线宽法是的为０．０２μｍ，一１８０℃时合成的硅沸石样品相比，低温合成的细晶粒硅沸石已上备内米级的若干特性，其正己烷吸附量反常增大；ＸＲＤ、ＦＴＩＲ、＾２９ＳｉＭＡＳ ＮＭＲ和ＴＧ／ＤＴＧ／ＤＴＡ的研究证明，其结构破坏温度和单斜／正交对称性     

TiO2负载非晶态合金NiB催化剂的制备、表征及HDS动力学研究

用等体积浸渍－还原法制备了负载型的ＮｉＢ／ＴｉＯ２（Ｂ／Ｎｉ＝５：１摩尔比）非晶态合金,并在相同条件下制备了ＮｉＢ／Ａｌ２Ｏ３（Ｂ／Ｎｉ＝５：１摩尔比）与之对照。用ＸＲＤ,ＳＥＭ和ＴＥＭ等表征方法比较了样品的非晶性质,在脉冲反色谱装置上以噻吩的ＨＤＳ反应为探针测定了ＮｉＢ／ＴｉＯ２、ＮｉＢ／Ａｌ２Ｏ３的反应活性,进行了动力学研究。结果证明,ＮｉＢ／ＴｉＯ２的低温活性远高于ＮｉＢ／Ａｌ２Ｏ３,其原因     

二氧化碳和丙烯直接合成甲基丙烯酸的NiPMo/TiO2催化剂的研究

用溶胶-凝胶法以磷钼酸(MPA)的镍盐溶液水解钛酸四丁酯制备了NiPMo/TiO2催化剂.使用ICP、 XRD、 TG-DTA、 IR、 TPD-MS和微反应技术研究了催化剂的化学组成、热稳定性、化学吸附性质和催化反应性能.杂多钼酸盐与TiO2通过O2-在TiO2表面发生了键合.在623 K下,杂多阴离子仍保持原有的Keggin结构.CO2在Lewis酸位Ni(Ⅱ)和Lewis碱位Ni-O-Mo的桥氧协同作用下生成CO2卧式吸附态Ni(Ⅱ)←O-(CO)←(O--Ni).丙烯有多种吸附态在催化剂上吸附.在563 K、 1 MPa和空速1500 h-1的反应条件下,丙烯的摩尔转化率为3.2%,产物MAA选择性为95%.     

Synthesis of 1-benzyloxypyrazin-2(1H)-one derivatives

Different approaches for the synthesis of 1-benzyloxypyrazin-2(1H)-one derivatives from simple amino acids have been investigated. A library of 33 precursors for the preparation of N-hydroxy pyrazinones was obtained in moderate to good yields.     

Toward new camptothecins. Part 6: Synthesis of crucial ketones and their use in Friedländer reaction

In the context of the preparation of camptothecin and luotonin A analogs, the synthesis of some key keto-precursors and their use in Friedländer condensation are described. This paper also focuses on the stability of these keto intermediates and emphasizes the major differences between indolizinones and pyrroloquinazolinones series. Noteworthy is also the report of some original structures isolated as by-products of some experiments.     

CoFe2O4自形成磁性液体场致结构化对磁化的影响

The Langevin paramagnetic theory can’t describe the relation between magnetization of ferrofluids and applied magnetic field. The structuralization of ferrofluids, which is considered the main influence factor of the magnetization, is regarded. The part of magnetization works is deposited when the structure is forming. This action influences the magnetization of ferrofluids directly or indirectly. On the base of the “compressing” model, the Langevin function that usually describes the magnetization of ferrofluid is modified, and a well-fitted curve is obtained. An equation of the relation between the equivalent volume fraction after being “compressed” and the intensity of magnetic field is discovered, which approximately describes the process of magnetization. The relation between the approximate initial susceptibility and the volume fraction can be obtained from modified formula.     

Highly regioselective Buchwald–Hartwig amination at C-2 of 2,4-dichloropyridine enabling a novel approach to 2,4-bisanilinopyridine (BAPyd) libraries

The highly regioselective Buchwald–Hartwig amination at C-2 of the cheap and readily accessible reagent, 2,4-dichloropyridine with a range of anilines and heterocyclic amines is described. This new methodology is robust and provides a facile access to 4-chloro-N-phenylpyridin-2-amines on 0.25 mol scale. These intermediates undergo a further Buchwald–Hartwig amination at higher temperature to enable rapid exploration of the chemical space at C-4 and to provide a library of 2,4-bisaminopyridines.     

KMnO4-mediated oxidative CN bond cleavage of tertiary amines: Synthesis of amides and sulfonamides

KMnO₄-mediated oxidative CN bond cleavage of tertiary amines producing secondary amine was introduced, which was trapped by electrophiles (acyl chloride and sulfonyl chloride) to form amides and sulfonamides. The reaction could take place at mild condition, tolerating a wide range of function groups and affording products in moderate to excellent yields.     

Chemistry of heterocyclic compounds at the A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences, over 50 years (Review)

The review contains a concise historical account and information on the most significant researches undertaken by the staff at the A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences on the Chemistry of Heterocyclic Compounds. Dedicated to Academician of the Russian Academy of Sciences B. A. Trofimov on his 70th jubilee. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1443–1502, October, 2008.     

A general and convenient synthesis of 4-(tosylmethyl)semicarbazones and their use in amidoalkylation of hydrogen,heteroatom, and carbon nucleophiles

A general synthesis of previously unknown semicarbazone-based α-amidoalkylating reagents, 4-(tosylmethyl)semicarbazones, has been developed. The synthesis involved three-component condensation of semicarbazones of aliphatic or aromatic aldehydes with the same or other aldehydes and p-toluenesulfinic acid. The scope and limitations of this reaction were investigated. The compounds obtained were demonstrated to be an efficient α-(4-semicarbazono)alkylating agents. They were reacted with H- (sodium borohydride), O- (sodium methylate), S- (sodium phenylthiolate), N- (pyrrolidine, sodium succinimide), P- (trialkyl phosphites), and C-nucleophiles (sodium diethyl malonate) to give the corresponding products of the tosyl group substitution, 4-substituted semicarbazones, including analogues of nitrofurazone. Among the prepared compounds tested in vitro for antibacterial and antifungal activity, three nitrofuryl-containing semicarbazones exhibited high biological activities with minimum inhibitory concentration (MIC) values of 8–32 μg/mL.     

Sulfur-directed metal-free and regiospecific methyl C(sp3)–H imidation of thioanisoles

Regiospecific and direct imidation of the methyl C(sp³)–H bond of thioanisoles is realized under mild and metal-free conditions with N-fluorobis(benzenesulfonyl)imide as an oxidant and nitrogen source. Proposed mechanism suggests that thionium ion intermediates and a Pummerer-type reaction are involved. The imidation has advantages such as high step-economy, excellent functionality tolerance, and regiospecificity, giving structurally diverse imidation products.     

Synthesis of novel chiral bidentate hydroxyalkyl-N-heterocyclic carbene ligands and their application in palladium-catalyzed Mizoroki–Heck couplings and asymmetric addition of diethylzinc to benzaldehyde

A small library of new chiral bidentate hydroxyalkyl-imidazolium salts 1 is conveniently synthesized on multi-gram scale from inexpensive and commercially available chiral pool amino acids. The corresponding carbenes, generated by deprotonation of imidazolium salts 1, in combination with palladium(II) chloride were tested in the Mizoroki–Heck coupling reaction. The most significant results in terms of yields and reactivities were achieved with low catalyst loading. The catalytic activities of these imidazolium salts were also investigated in the asymmetric addition of diethylzinc to benzaldehyde. The use of MgO nanoparticles as an additive in conjunction with these ligands played a crucial role in increasing the efficiency of these reactions.