Mn－Ag／γ－Al_2O_3催化剂中氧的性能

本文运用ＴＰＲ、ＴＰＤ－ＭＳ、ＸＲＤ等技术研究了Ｍｎ－Ａｇ／γ－Ａｌ_２Ｏ_３催化剂的还原性能和再氧化能力．结果表明，Ｍｎ－Ａｇ／γ－Ａｌ_２Ｏ_３中银物相由Ａｇ￣０和Ａｇ_２Ｏ组成，锰物相由β－ＭｎＯ_２和Ｍｎ２Ｏ_３组成．Ｍｎ／γ－Ａｌ_２Ｏ_３催化剂的ＴＰＲ有二个还原峰，分别是ＭｎＯ_２和Ｍｎ_２Ｏ_３的还原．Ａｇ促使ＭｎＯ_２和Ｍｎ_２Ｏ_３的还原明显向低温方向移动，而且ＭｎＯ_２和Ｍｎ_２Ｏ_３的还原峰融合成一个还原峰．Ｍｎ－Ａｇ／γ－Ａｌ_２Ｏ_３的ＴＰＤ有三个脱氧峰，随着Ａｇ含量增加，峰Ⅰ向高温方向移动，Ｍｎ￣（４＋）２ｐ３／２的电子结合能增加，并且催化剂的再氧化能力增强．催化剂ＣＯ的氧化活性与催化剂的再氧化能力有很好的对应关系．     

负载型贵金属催化剂的制备化学－载体等电点对Pd／A1_2O_3催化剂结构与催化性能的影响

本文通过化学修饰的方法改变了γ－Ａｌ_２Ｏ_３载体等电点（ＩＥＰＳ），并用具有不同等电点的Ａｌ_２Ｏ_３作载体，以（ＮＨ_４）_２ＰｄＣｌ４为活性组分前身制备了一系列Ｐｄ／Ａｌ_２Ｏ_３催化剂，在固定床微反色谱装置上考察了其对ＣＯ氧化的催化活性，用Ｈｉ—Ｏ_２滴定、紫外漫反射光谱（ＤＲＳ）、透射电子显微镜（ＴＥＭ）中的能量色散谱（ＥＤＸＳ）等方法对上述催化剂进行了表征，结果表明：Ａｌ_２Ｏ_３的等电点（ＩＥＰＳ）对所得催化剂中金属分散度和浓度分布都有明显影响，ＩＥＰＳ越高。活性组分越靠近外表面，在相同担载量下，其分散度也越高。这主要是由于载体ＩＥＰＳ的改变，导致了（ＮＨ_４）_２ＰｄＣｌ_４在γ－Ａｌ_２Ｏ_３上吸附机理的变化，并使所得催化剂对ＣＯ氧化的催化活性发生了规律性的变化。     

CuO／γ－Al_2O_3中热稳定助剂作用的探讨

用等量共浸法和分浸法制备了含Ｃａ、Ｓｒ、Ｂａ、Ｍｇ、Ｚｒ和Ｌａ助剂的ＣｕＯ／γ－Ａｌ_２Ｏ_３催化剂（ＣｕＯ／Ａｌ_２Ｏ_３＝８ｗｔ％，Ｍ／Ｃｕ（原子比）＝０．１５，Ｌａ／Ｃｕ＝０．３５）．用ＸＲＤ和ＸＰＳ等考察了在高温７５０℃、９５０℃和１０５０℃老化后的相结构和ＣＯ氧化活性，实验表明所有助剂均有不同程度的抗烧结和抗相变作用。其中Ｌａ、Ｃａ和Ｚｒ的效果最好。分浸法比共浸法好。在９５０℃老化后，ＣｕＡｌ_２Ｏ_４和α－Ａｌ_２Ｏ_３同步产生；随老化温度增高，ＣＯ氧化活性有所下降。分浸法制备的含Ｚｒ样品在９５０℃老化后活性最高。从γ－Ａｌ_２Ｏ_３缺陷尖晶石特征及高温脱结构水过程，探讨了助剂抑制α－Ａｌ_２Ｏ_３生成的原因。     

掺杂Pr对VPO催化剂性质的影响

在ＶＰＯ催化剂中添加Ｐｒ，用ＸＲＤ，ＬＲＳ，ＸＰＳ，ＥＳＲ和＾３１Ｐ固体核磁共振考察了催化剂的相组成和钒的氧化态，用ＮＨ３－ＴＰＤ和吡啶吸会原位红外光谱表征了催化剂表面的酸量。将催化剂应用于正丁烷选择氧化生成顺酐的反应中，实验结果表明，当Ｐｒ／Ｖ原子比＝０．０５时，活性相（ＶＯ）２Ｐ２Ｏ７的量增加，表面酸性增强，正丁烷转化率和生成顺酐的选择性都有所提高，而Ｐｒ／Ｖ≥０．１０时，（ＶＯ）２Ｐ２Ｏ７的     

负载型La0.8Sr0.2MnO3燃烧催化剂的载体效应

用浸渍法制备负载型Ｌａ_（０．８）Ｓｒ_（０．２）Ｍｎｏ_３燃烧催化剂,比较了γ－ＡＩ_２Ｏ_３、α－ＡＩ_２Ｏ_３、堇青石（２ＭｇＯ·２Ａｌ_２Ｏ_３、５ＳｉＯ_２）和ＺｒＯ_2四种载体的负载效果．用ＸＲＤ,ＤＰＲ着重研究了γ－Ａｌ_２Ｏ_３载体上由于负载量不同、焙烧温度不同引起的催化剂物相变化和二甲苯完全氧化的催化活性变化．     

铁助剂对Pd／Al2O3催化剂抗硫性能的影响

借助ＣＯ探针分子原位红外（ｉｎ－ｓｉｔｕＩＲ）、ＴＥＭ（ＥＤＳ）、ＸＰＳ和ＸＲＤ对一系列Ｐｄ－Ｆｅ／Ａｌ_２Ｏ_３、Ｐｄ－Ｐｔ／Ａｌ_２Ｏ_３和Ｐｄ（或Ｐｔ）／Ａｌ_２Ｏ_３模型催化剂进行了表征，结果表明，硫在中毒Ｐｄ（或Ｐｔ）／Ａｌ_２Ｏ_３时，毒物Ｈ_２Ｓ优先吸附于催化剂的多位活性中心上，主要以电子效应影响催化剂的活性．铁的引入，提高了活性组分Ｐｄ的分散度，多位活性中心的减少不利于Ｈ_２Ｓ在催化剂上的吸附；Ｐｄ－Ｆｅ协同作用的结果，增强了催化剂对吸附Ｓ~（２－）氧化成毒性较小的Ｓ~（６＋）或可逸出系统的ＳＯ_２的能力，从而明显地提高了催化剂的抗硫中毒能力．     

正戊烷选择性氧化用VPO催化剂的合成新方法(英)

研究了 合成 Ｖ Ｐ Ｏ 催化剂 时还 原 溶剂 对 Ｖ Ｐ Ｏ 的结 构及 催 化性 能的 影 响． Ｖ Ｐ Ｏ 的 合 成方法如下 ： （１） Ｖ２ Ｏ５ 与 Ｈ３ Ｐ Ｏ４ 反 应生成磷 酸钒; （２） 用 不同 的还 原溶 剂还 原磷 酸钒 得到 Ｖ Ｐ Ｏ 催化剂前身 ; （３） 活化 Ｖ Ｐ Ｏ 催化 剂前身． 研究 的还原溶 剂有 ： 异 丁醇 、异 丁醇苯甲 醇、异丁 醇石 油醚和正己 醇． 结 果表明, 使用异 丁醇石 油醚 作还 原 溶剂 ,只 能生 成 Ｖ Ｏ Ｈ Ｐ Ｏ４·０５ Ｈ２ Ｏ 晶 体; 使 用其它溶剂 则会生 成 Ｖ Ｏ（ Ｈ２ Ｐ Ｏ４） ２ 和 Ｖ Ｏ Ｈ Ｐ Ｏ４·０５ Ｈ２ Ｏ 两种 晶体,但使 用的溶 剂生 成这 两种 晶体 的相对量大 不相同 ． 经 活 化 后, 不 同 还 原 溶 剂 合 成 的 Ｖ Ｐ Ｏ 只 含（ Ｖ Ｏ）２ Ｐ２ Ｏ７ 晶 相． 在 活 化 过 程 中, Ｖ Ｏ（ Ｈ２ Ｐ Ｏ４） ２ 转变成 无定形化 合物． Ｖ Ｏ Ｈ Ｐ Ｏ４·０５ Ｈ２ Ｏ 晶相 含量较 高的催化 剂前身, 经活 化后 催化剂中（ Ｖ Ｏ）２ Ｐ２ Ｏ７ 晶 相含量相 对较高 ,其催化活 性也相 对较高     

Ag／γ－Al_2O_3催化剂的TPR和TPD研究

本文运用ＴＰＤ－ＭＳ、ＴＰＲ等方法研究了Ａｇ／γ－Ａｌ_２Ｏ_３催化剂的氧脱附和还原性能。结果表明，Ａｇ／γ－Ａｌ_２Ｏ_３催化剂表面银物相由Ａｇ０和Ａｇ＋（Ａｇ２Ｏ）组成，其中Ａｇ＋所占比例随负载量增加而减少。Ａｇ／γ－Ａｌ_２Ｏ_３催化剂有三个脱氧峰，并且随着Ａｇ负载量的增加，脱氧峰从高温向低温依次出现。低温脱氧峰（３７０℃）归属为结晶态Ａｇ２Ｏ的分解，高温脱氧峰（６５０和８００℃）为分散在γ－Ａｌ_２Ｏ_３表面并且与Ａｌ_２Ｏ_３发生相互作用的Ａｇ_２Ｏ的分解。ＴＰＲ有三个还原峰；高温峰（２３０℃）为结晶态Ａｇ_２Ｏ的还原，低温峰（１００和１２０℃）为分散在γ－Ａｌ_２Ｏ_３表面的Ａｇ_２Ｏ的还原。     

环戊烷选择性氧化用VPO催化剂的合成新方法

研究了ＶＰＯ催化剂时还原溶剂对ＶＰＯ的结构及催化性能的影响,ＶＰＯ的合成方法如下：（１）Ｖ２Ｏ５与Ｈ３ＰＯ４反应生成磷酸钒;（２）用不同的还原溶剂还原磷酸钒得到ＶＰＯ催化剂前身;（３）活化ＶＰＯ催化剂前身,研究的还原溶剂有;异丁醇,异丁醇－苯甲醇,异丁醇－石油醚和正己醇。结果表明,使用异丁醇－石油醚作还原溶剂,只能生成ＶＯＨＰＯ４．０．５Ｈ２Ｏ晶体;使用其它溶剂则会生成ＶＯ（Ｈ２ＰＯ４）２和ＶＯＨ     

担载镍催化剂上乙炔与甲酸甲酯加氢酯化合成丙烯酸甲酯:担载量和焙烧温度的影响(英文)

以ＮｉＯ担载量为０．０８ｗｔ％～１８．７ｗｔ％及焙烧温度为６２３ Ｋ～８７３ Ｋ的ＮｉＯ／Ａｌ２Ｏ３催化剂进行乙炔与甲酸甲酯的加氢酯化反应,并结合ＴＰＲ、ＸＰＳ、ＸＲＤ和ＢＥＴ技术对催化剂进行表征。催化剂在制备过程中,镍离子与载体氧化铝间的相互作用产生两种不同的镍物种,ＮｉＯ晶相和ＮｉＡｌ２Ｏ４类物种,它们间的比例随担载量及焙烧温度而异,因而表现出其对乙炔与甲酸甲酯加氢酯化不同的反应性能。实验结果表明,在７７３ Ｋ焙烧的１０Ｗｔ％ＮｉＯ／Ａｌ_２Ｏ_３最适合乙炔与甲酸甲酯的加氢酯化反应。     

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.