金属络合物制备分子筛负载金属催化剂的CO加氢反应性能

应用Ｙ分子筛吸附Ｆｅ（ＣＯ）５、Ｃｏ（ＣＯ）３ＮＯ和Ｍｏ（ＣＯ）６的温和热分解制备分子筛负载金属催化剂，从分子筛交换阳离子和吸附金属络合物之间的相互作用说明其ＣＯ加氢产物的分布特点。实验结果表明，分子筛内阳离子和吸附金属络合物间的相互作用显著影响制得催化剂的结构和反应的产物分布。由于金属络合物和分子筛内阳离子间的电子转移，使ＮｉＹ附载金属催化剂显示出高的ＣＯ转化率和甲烷选择性。在ＣｕＹ中，这种电子     

CoAPSO－34分子筛的合成与性能

以三乙胺为模板剂，在碱性条件下用水热晶化法将钴元素引入了硅磷铝分子筛骨架，合成出ＣｏＡＰＳＯ－３４分子筛．实验表明，在碱性介质中以低价态引入的钴元素首先转化为高价态Ｃｏ（Ⅲ），然后才进入分子筛骨架。利用Ｘ射线粉末衍射和红外光谱对其进行了结构分析，确认钴元素进入了分子筛骨架．利用程序升温氨脱附和氨法红外光谱考察了ＣｏＡＰＳＯ－３４的表面酸性．将ＣｏＡＰＳＯ－３４用作甲醇转化的催化剂时，随钴含量增高，催化剂稳定性下降，反应产物中Ｃ＝２～Ｃ＝４烯烃的选择性升高     

溶剂化金属原子浸渍法制备聚合物固载Co—Ag催化剂：Ⅲ.聚合？…

应用溶剂化金属原子浸渍法制血了四中不同比表面积树脂固载的Ｃｏ－Ａｇ双金属催化剂。射线衍射（ＸＲＤ）和磁测定结果表明，随着树脂比表面积的增大，具有相同金属含量的催化剂Ｃｏ和Ａｇ的颗粒减小，分散度增大，因而催化剂在二丙酮醇加氢以及燃料电池电极上氧还原的催化活性增大。     

合成气在铁锰/沸石催化剂上合成低碳烯烃的研究 Ⅳ.添加碱性助剂的DM-Ⅱ高硅沸石担载型催化剂的性能

在DM-Ⅱ高硅沸石担载的Fe-MnO催化剂中添加碱性助剂可提高催化剂的活性及C_2~=～C_4~=烯烃选择性,且随着碱性增强,催化剂性能不断改善,随助剂MnO含量的增加,低碳烯烃的选择性不断提高,而催化剂活性有一极大值。研究表明,金属活性组分以适当的粒度分散在分子筛表面,MnO可提高其分散度,添加碱性助剂不利于金属组分的还原,但其“电子效应”却显著改善了催化剂性能,MnO能促进铁的还原,从而提高了催化剂的活性。     

Rh2,Rh4高分散催化剂的制备及分散度与CO吸附态关系的研究

建立了一整套Ｒｈ簇高分散催化剂的制备技术和方法，制备出了分散的Ｒｈ＿２／Ａｌ＿２Ｏ＿３和Ｒｈ＿４／Ａｌ＿２Ｏ＿３簇催化剂。Ｈ＿２化学吸附表明这些样品具有很高的金属分散度，且分散度随Ｒｈ簇担载量的增加而降低。ＣＯ吸附态测定表明，当簇合物的Ｒｈ担载量（ｗ％Ｒｈ）为０．７％时分散度最高。ＣＯ分子在催化剂上只有一种吸附方式─—孪生吸附，实现了ＣＯ吸附态的“分离”，即催化剂上只存在一种吸附中心。表明催化剂的金属粒度已达到均一。这一结果还表明可通过原子簇衍生催化剂的方法来控制ＣＯ分子在Ｒｈ催化剂上的吸附方式。催化剂制备过程的原位红外光谱测试结果表明：Ｒｈ簇与γ－Ａｌ＿２Ｏ＿３作用形成高分散是一个很快的过程。     

W-Ni/Al2O3-USY催化剂中USY的作用

采用ＥＳＣＡ，ＴＰＲ及高压连续流动反应色谱等技术研究了在Ｗ－Ｎｉ／Ａｌ２Ｏ３中引入超稳Ｙ型分子筛对载体表面性质及催化剂加氢脱氮活性的影响。结果表明：ＵＳＹ可明显改善Ｗ和Ｎｉ的分散状态，提高催化剂的总酸，并可调变Ｂ酸和Ｌ酸的分布；加入ＵＳＹ可提高催化剂的比表面积，但不利于发挥Ｎｉ的助剂作用；加入适宜量的ＵＳＹ，可明显提高催化剂的加氢脱氮活性。     

Co助剂对稀燃NOx阱Pt/Ba-Al-O结构和性能的影响

 采用共沉淀－浸渍法制备了Pt／Co－Ba－Al－O催化剂，用X射线衍射、X射线吸收近边结构和扩展X射线吸收精细结构等手段表征了催化剂的微观结构，并在连续流动微型反应器上测定了催化剂对NOx的储存性能．载体经过800℃焙烧后，Co物种主要以四面体配位的铝酸钴相存在．在富氧条件下，高分散的小颗粒铝酸钴相促进了NO向NO2的转化，大大改善了催化剂对NOx的储存性能．铂物种则以小的金属原子簇形式存在，分散度很高．钴助剂的添加改善了氧化铝相的分散度，抑制了金属铂原子簇与载体的相互作用，使铂在催化剂表面分散得更均匀，从而有利于NOx的储存．     

溶剂化金属原子浸渍法制备的Ni-Ag/γ-Al_2O_3催化剂的催化性质研究

应用溶剂化金属原子浸渍（ＳＭＡＩ）法和普通浸渍（ＣＩ）法制备了金属含量相同的γＡｌ２Ｏ３负载ＮｉＡｇ双金属催化剂。研究了这些催化剂在甲苯和二丙酮醇加氢以及ＣＯ２甲醇化反应中的催化性质，结果表明与组成相同的普通浸渍法催化剂相比，在所有这些反应中ＳＭＡＩ催化剂都显示出较高的催化活性，这是因为ＳＭＡＩ催化剂具有较高的分散度和还原度（零价金属百分比）。     

分子筛限域单原子金属催化剂的研究进展

分子筛由于具有规则的微孔孔道结构、 较大的表面积、 优异的(水)热稳定性, 被认为是限域合成超小尺寸金属物种的理想载体. 近年来, 分子筛限域单原子金属催化剂由于超高的金属分散度、 接近100%的金属利用率以及独特的电子结构, 被广泛地应用于重要的催化反应和气体吸附分离过程. 本文系统地总结了近年来分子筛限域不同类型单原子金属催化剂的合成策略, 以及其在多相催化和气体分离等领域的研究进展. 最后, 提出了分子筛限域单原子金属催化剂在合成与表征方面存在的挑战和未来的发展方向.     

加氢处理催化剂载体中Y型分子筛组分对催化剂表面性质和催化性能的影响

应用ＸＲＤ，ＸＰＳ，ＩＲ－ＴＰＤ，ＣＯ２和ＮＯ吸附及正庚烷裂解和噻吩加氢脱硫脉冲微反等方法，研究了加氢处理催化剂载体经Ｙ型分子筛改性前后各种性质的变化，结果表明，载体经Ｙ型分子筛改性后，催化剂的Ｂ酸、正庚烷裂解活性和异构选择性明显提高，Ｙ型分子筛以分散的形式分布于γ－Ａｌ２Ｏ３表面，减少了载体表面的空位铝，该催化剂中有盯当一部分金属组分进入Ｙ型分子筛孔道与３其Ｂ酸位作用，与ＮｉＱ／γＡｌ２Ｏ３相比     

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.