脱铝沸石羟基窝的表征

NH4Y和NaY沸石用草酸溶液脱铝制备的样品，用红外光谱测定了表征“羟基窝”的3710cm-1处的背底吸光度（A3710）．并考察了其热稳定性；用DTA和TGA建立了定量测定“羟基窝”的方法，并测定了各样品的“羟基窝”浓度，样品的“羟基窝”浓度与其实际脱铝数相对应     

丝光沸石的疏水化研究

采用不同的脱铝方法得到Ｓｉ／Ａｌ比为１５～１１２的丝光沸石，用ＩＲ方法测定了样品的脱铝空穴含量，并考察样品的热稳定性和疏水性，实验结果表明，脱铝后形成的大量末端硅羟基仍有亲水性，因而单纯酸脱铝疏水化效果有限，用水蒸汽处理或（ＮＨ４）２ＳｉＦ６补硅的方法使沸石表面硅羟基转变成≡Ｓｉ－Ｏ－Ｓｉ≡键，能显著地提高沸石疏水性。     

草酸脱铝Y沸石的性质

草酸与草酸铵脱铝的Ｙ沸石，具有八面沸石结构和良好的结晶度。羟基红外光谱和吡啶吸附的红外光谱表明，在脱铝Ｙ沸石的骨架中存在着铝空位，这种缺铝Ｙ沸石中由３５５０ｃｍ＾－１表征的小笼羟基更具开放性，但稳定性较差，在升温过程中，它比３６４０ｃｍ＾－１表征的大笼羟基更易脱除。吡啶与ＣＯ双探针分子红外光谱的研究表明，升温脱羟基过程伴随着与Ｌｅｗｉｓ酸有关的非骨架铝的生成，低温Ｎ２吸附的结果显示，缺铝Ｙ沸石中还     

干粉合成中氟离子对ZSM—5沸石的结构定向作用

考察了Ｎａ２Ｏ－ＳｉＯ２－Ａｌ２Ｏ３－ＥＤＡ干粉体系中是否加入ＮａＦ以及加入量对产品物相及结晶度的影响。结果表明,当反应体系不加ＮａＦ时,产物为结晶度高的单一晶相的ＺＳＭ－３５沸石,而体系中加入ＮａＦ时,产品中有ＺＳＭ－５沸石物相出现,而且随着ＮａＦ加入量的增加,产品物相完全转化为具有很高结晶度的单一相ＺＳＭ－５沸石。说明氟离子对干粉体系中ＺＳＭ－５沸石的生成具有明显的结构定向作用     

新型CuCl／Hβ沸石羰基化催化剂的制备与原位红外光谱表征

采用固态离子交换法在沸石中直接引进Ｃｕ（Ⅰ）活性中心,ＣｕＣｌ分子在Ｈβ沸石中与Ｈ＾＋交换和在沸石内表面单层分散两个过程同时发生,负载阈值为２１．２％（ＣｕＣｌ％）,调节ＣｕＣｌ和Ｈβ的配比,可得到从桥羟基被部分交换到所有羟基被完全交换的ＣｕＣｌ／Ｈβ从化剂。     

以拟薄水铝石为铝源合成的β沸石的表征和催化性能(英文)

考察了以拟薄水铝石为铝源、固体硅胶为硅源、四乙基氢氧化铵为模板剂时不同晶化混合液ＳｉＯ２／Ａｌ２Ｏ３比和不同晶化温度对β沸石合成的影响。ＸＲＤ、ＴＧＡ、ＩＣＰ及ＳＥＭ研究结果表明,在晶化混合液ＳｉＯ２／Ａｌ２Ｏ３比为２０至５０之间、晶化温度为１４０℃～１６０℃范围内能合成出高结晶度的β沸石,且β沸石硅铝比与晶化混合液硅铝比呈良好的线性关系：ＴＧＡ总失重量随β沸石硅铝比增加而增加,晶化温度对β沸石的晶粒度没有明显影响。此外,所制备的Ｈβ沸石对甲苯与Ｃ９芳烃歧化和烷基转移反应具有良好的催化性能。     

高活性沸石酯化催化剂的研究

用硼酸和硫酸对含Ａｌ２Ｏ３的β和ＺＳＭ５沸石进行处理，制备了一系列沸石ＭｘＯｙ和ＳＯ２４／沸石ＭｘＯｙ）催化剂。用ＮＨ３ＴＰＤ和Ｈａｍｍｅｔｔ指示剂法测定了催化剂的表面酸性。对Ｈ２ＳＯ４处理的样品进行了Ｘ射线物相分析。用ＢＥＴ法测定了Ｈβ及ＨＺＳＭ５３８对乙酸的吸附等温线和饱和吸附量。对催化剂的活性，均通过乙酸和乙醇在液相、９０℃和不分水条件下的酯化进行表征。结果表明，ＨβＡｌ２Ｏ３经硼酸和硫酸处理后，乙酸的转化率由３９．５３％提高到５４．９２％。ＨＺＳＭ５３８Ａｌ２Ｏ３经同样处理后，乙酸的转化率由２４．４５％提高到４４．８７％。ＳＯ２４／沸石ＭｘＯｙ的最佳焙烧温度范围是５００～５５０℃。此外，在固定床反应器内于１００～１３０℃和ＬＨＳＶ为６ｈ１的条件下，对ＳＯ２４／ＨβＡｌ２Ｏ３Ｂ２Ｏ３的活性位的稳定性进行了初步实验。反应在１１０℃连续进行１２ｈ后，乙酸的转化率始终稳定在６９％左右。     

酸处理对β沸石结构和酸性的影响

考察了酸处理对β沸石的酸性的影响，发现β沸石的骨架虽易脱铝，但能抗５ｍｏｌ／ＬＨＣｌ，ｄ ５ｍｏｌ／ＬＨＣｌ中，β沸石的脱铝程度可达８０．０％以上，β-沸石的孔容影响不大，ＮＨ３－ＴＰＯ及Ｐｙ－Ｉｒ结果表明，β沸石经酸处理后，其强度增加，在樱椋粒欤剑常福秆飞洗锏阶钋浚砻嫠嵋裕趟嵛鳎宜妫樱椋粒毂鹊脑黾佣銮俊?     

六硅Y沸石的研制及性能

ＬｉＮａＹ沸石经ＳｉＣｌ４气相同晶脱铝补硅后制得系列高硅铝比,高结晶度的Ｙ沸石,用低温氮吸附法,救是样品对Ｎ２的吸附－－脱附等温线,从而计算其比表面和孔体积,并采用ＢＪＨ模型计算孔径分布。用真空重量法测定了四种Ｃ６化合物（正己烷,２,３－二甲基丁烷、苯、环己烷）的吸附等温线,探讨吸附量与吸附物的性能（极性、几何构型）,吸附量一吸附剂脱铝深度的关系,从而得到,经ＳｉＣｌ４同晶取代后Ｙ沸石的孔结构和表     

在水蒸气气氛中合成沸石分子筛及其特性

无定型硅铝凝胶－Ｎａ２Ｏ－Ａｌ２Ｏ３－ＳｉＯ２－Ｈ２Ｏ在水蒸气相中可以晶化合成出ＬＴＡ，ＦＡＵ和ＭＯＲ沸石晶体。本文重点研究了ＭＯＲ沸石的晶化条件和物理化学特性。     

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.     

α-Amino acid derived enaminones and their application in the synthesis of N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates and other heterocycles

A new and simple synthesis of novel N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates, which exist in equilibrium with their 4-oxo tautomers, has been developed in two steps starting from N-protected α-amino acids. The key intermediates are enaminones, which can also be isolated, characterized, and used for the construction of other functionalized heterocycles, before they spontaneously decompose to pyrrole products. 4-Hydroxypyrroles are prone to partial aerial oxidation but can be efficiently alkylated or reduced to stable polysubstituted pyrrolidine derivatives.     

Specific intramolecular aromatic CH insertion of diazosulfonamides

The chemoselectivity in the intramolecular CH insertion of various diazosulfonamides has been experimentally studied. The results reveal that the aliphatic 1,4-, 1,5-, or 1,6-C(sp³)?H insertions of diazosulfonamides are not accessible, while the aromatic 1,5-C(sp²)?H insertion can be realized specifically by adjusting the diazo-adjacent group. In addition, the general chemoselectivities in the intramolecular CH insertions of diazosulfonyl compounds are summarized. Generally, diazosulfones undergo both aromatic 1,5-C(sp²)?H and aliphatic 1,5- and 1,6-C(sp³)?H insertions, while diazosulfonates undergo aliphatic 1,5- and 1,6-C(sp³)?H insertions. However, diazosulfonamides only undergo aromatic 1,5-C(sp²)?H insertion.     

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.     

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.     

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.     

N-Heterocyclic carbene-palladacyclic complexes: synthesis,characterization and their applications in the C-N coupling and α-arylation of ketones using aryl chlorides

N-Heterocyclic carbene-palladacyclic complexes 3 were successfully achieved in a one-pot procedure under mild conditions. The structure of 3a was unambiguously confirmed by X-ray single crystal diffraction and it was an active catalyst in the Buchwald-Hartwig amination and α-arylation of ketones even at very low catalyst loadings (0.01?mol%).     

Iodine-mediated oxidative Pictet-Spengler reaction using terminal alkyne as the 2-oxoaldehyde surrogate for the synthesis of 1-aroyl-β-carbolines and fused-nitrogen heterocycles

An efficient iodine-mediated oxidative Pictet-Spengler reaction in dimethyl sulphoxide (DMSO) using terminal alkynes as the 2-oxoaldehyde surrogate for the synthesis of aryl (9H-pyrido[3,4-b]indol-1-yl)methanones is described. The scope of the protocol includes the total synthesis of Fascaplysin, Eudistomins Y₁ and Y₂. The methodology is extended for preparing pyrrolo[1,2-a]-quinoxaline and indolo[1,5-a]quinoxaline derivatives. The utility of 1-aroyl-β-carbolines was demonstrated by performing palladium-catalyzed β-carboline directed ortho-C(sp2)-H functionalization of the phenyl ring with thiomethyl (SMe) group using DMSO as source and for accessing 4-aryl-canthin-6-ones.     

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.