β沸石中铝的状态及归属

用FTIR方法对β沸石中铝的状态进行了研究．结果表明，在脱除模板剂的β沸石中存在着三种状态的铝，即骨架铝、非骨架铝和过度态铝．铝的存在状态与平衡阳离子的性质密切相关，当平衡阳离子为高电子亲和性的H 时，β沸石的骨架发生扭曲而具有较大的张力，使得Al-O键断裂，铝经过渡态移出骨架，成为非骨架铝．当H 被Na 等离子取代后，骨架形变得以缓解，过渡态铝重又恢复骨架四面体配位，而阳离子态的非骨架铝物种则被交换进入溶液．     

硼改性对Hβ沸石表面酸性及丙烯与异丙醇醚化反应性能的影响

研究了硼改性的Ｈβ沸石表面酸性变化及其对丙烯与异丙醇醚化反应性能的影响。样品Ｂ２Ｏ３－Ｈβ的酸量随Ｂ２Ｏ３含量增加而增多。含量超过３％时酸量基本不变；对于Ｂ２Ｏ３－Ｈβ－Ａｌ２Ｏ３催化剂，Ｂ２Ｏ３使总酸量明显增大，并以Ｌ酸中心增加为主；Ａｌ２Ｏ３粘合剂的存在促进了Ｂ２Ｏ３与Ｈβ沸石间的相互作用；丙烯转化率及水的产率分别与Ｌ酸和Ｂ酸中心有很好的对应关系。丙烯与异丙醇的醚化反应主要在Ｌ酸中心上进行。     

HF处理对β沸石结构和酸性的影响

 采用FT－IR，XRD，BET，TPD，元素分析及孔结构和比表面积测试等手段研究了骨架外氧化铝存在的条件下，HF处理对Hβ沸石结构和\r\n酸性的影响，并提出了HF改性机理．结果表明，在酸处理和氟化的双重影响下，桥形羟基（3605cm－1）、骨架外铝物种的羟基（3660cm－1）和不稳定骨架铝物种的高频羟基（3782cm－1）逐渐减少，而链末端Si羟基（3745cm－1）和羟基窝附近Si羟基（3730cm－1）逐渐增多．同时，随着处理程度的加深，β沸石的总酸量逐渐减少并趋于稳定，强弱酸比值逐渐增大，B酸量先降后升，L酸量逐渐下降．但是，改性程度较深时β沸石的酸性变化不大．     

β-沸石骨架铝化改性的红外光谱

β沸石是以有机胺为模板剂合成的高硅沸石．为在孔道中进行吸附和催化反应,通常是在空气中 (５５０℃ )进行焙烧,将有机胺脱除并使质子酸中心形成．但这种脱模板剂方法,会造成骨架脱铝［１ -４］,使质子酸中心显著减少．β沸石固有结构中存在着孔道位错和结构空穴,空气中焙烧脱有机胺可能会进一步损伤沸石的骨架结构［４,５］．沸石骨架改性已发展了多种铝化方法［６ -８］．有的研究工作表明,通常用红外光谱和ＭＡＳＮＭＲ表征的非骨架铝,在温和的条件下,例如回馏温度下的离子交换或者在较低温度下 (１００℃或室温 )与碱反应就可…     

β沸石在丙烯醚化反应中的催化性能

研究了β沸石在不同焙烧温度和加入粘合剂条件下对丙烯与异丙醇合成异丙醚的催化性能。并通过ＸＲＤ、ＸＰＳ、ＮＨ３－ＴＰＤ、ＦＴ－ＩＲ及化学吸附等手段表征了β沸石的物理化学性质。结果表明：焙烧对丙烯醚化反应存在一合适的温度范围；Ａｌ２Ｏ３粘合剂提高了丙烯转化率，降低了异丙醇脱水活性；粘合剂使沸石表面上Ｌ酸中心的比例增加；丙烯醚化反应与Ｌ酸中心存在较好的对应关系，而异丙醇脱水反应与Ｂ酸中心对应；高温焙烧β沸石使骨架铝向表面迁移，粘合剂Ａｌ２Ｏ３能抑制沸石的晶胞收缩。     

高硅沸石计算晶格能与骨架拓扑结构相关

应用晶格能极小化技术计算了十九种骨架拓扑结构的高硅沸石的全硅骨架晶格能。采用一元线性回归分析、多元线性回归分析和人工神经网络误差反传算法（ＢＰ），将这十九种拓扑结构高硅沸石的全硅骨架晶格能计算值与它们的骨架拓扑结构参数相关。预测结果与计算各能符合良好，表明晶格能与配位序（Ｎ↑－２￣Ｎ↑－４）具有优良的多元线性关系。利用多元线性回归方程对七种结构的高硅沸石的全硅骨架晶格能进行了预测。     

沸石电流变液材料的研究

系统地研究了沸石的由离子类型、数目、骨架的孔道大小和结构特性对沸石电流变液性能的影响. 证实了阳离子在电场中的迁移所引起的晶粒极化是Y，A和M等沸石电流变特性的基础，指出了较大的孔径和具有足够多易迁移的阳离子是该类沸石具有较好电流变性的的前提．根据NaZSM－5沸石在高电场中与其它沸石表现不同，具有屈服应力大而漏电流小的特点，提出了沸石晶粒极化还可能存在的另一种新的晶格变形机理．     

沸石的骨架结构与酸强度

沸石分子筛是应用广泛的固体酸催化剂，其催化性能与沸石质子酸的强度和密度密切有关，对沸石酸性的研究是沸石催化领域内一个永恒的课题，国内外许多学者对此进行了长期工作，然而至今仍有许多问题认识不一致，关于沸石骨架结构与酸性的关系也是其中争议较多的问题之一．Sohn等N曾经根据脱铝Y沸石和ZSM－5沸石上正己烷反应结果，笼统地认为Si／Al比超过一定值以后，不同骨架结构的沸石的酸强度相同，催化活性只与酸位密度有关．Barthomeuf[2]则从沸石的结构参数出发，提出了一种较为精确的说法，即沸石的酸强度与骨架中铝的拓扑密度有…     

β沸石骨架稳定性与表面酸性的红外光谱研究

用红外光谱法研究了真空热脱附和空气中焙烧两种不同的方法脱除模板剂对Hβ沸石骨架结构稳定性和表面酸性的影响.结果表明,在真空条件下加热脱除模板剂,其骨架结构保持完好且质子酸中心最多.而在空气中焙烧脱除模板剂,导致沸石骨架部分脱铝,形成大量的Lewis酸且耐酸性极差.     

MCM－22沸石的孔结构和酸分布特性对苯与丙烯烷基化反应产物分布的影响

 根据测试结果，得到了MCM－22和具有相同硅铝比的β沸石的酸中心数及其分布，系统地研究了反应条件对苯与丙烯烷基化反应产物分布的影响；结合扩散系数与扩散势能，讨论了产物分布与MCM－22沸石孔道及酸性质的关系，并与β沸石进行了比较．苯烷基化反应发生在MCM－22沸石的外表面上，其空间位阻较小；在相同的反应条件下，与发生在β沸石十二元环孔道内的苯烷基化反应相比，异丙苯的选择性低2％～4％，二异丙苯的选择性高0．5％～5％，三异丙苯的生成量多10余倍．位于MCM－22沸石十元环二维正弦波形孔道的B酸中心，由于空间位阻大，很难发生苯烷基化反应，但可发生丙烯齐聚反应，故MCM－22沸石上有较多的丙烯齐聚物生成．β沸石上生成正丙苯的量是MCM－22沸石上的3～4倍．     

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.     

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.     

Facile synthesis of bicyclic 1-arylpyrazol-5-ones

In this Letter, we described a facile method for constructing fused bicyclic 1-arylpyrazol-5-one ring system. We employed various methylene-containing carboxylic acids as the substrates and proved that the pyrazolone ring closure requires activated methylene group in intermediate II. Accordingly, a series of structurally diversified, fused bicyclic 1-arylpyrazol-5-ones was prepared in moderate to high yields using the requisite substrates.     

Synthesis of pyrrolo[1,2-a]pyrazines and pyrazino[1,2-a]indoles by Curtius reaction in Morita-Baylis-Hillman derivatives

Synthesis of substituted pyrrolo[1,2-a]pyrazines and pyrazino[1,2-a]indoles from the Morita-Baylis-Hillman derivatives of acrylates via saponification followed by Curtius reaction is described.     

正丁胺对激光染料荧光谱影响的研究

用正丁胺作为碳源,采用射频辉光放电制备碳膜,选用激光染料R6G和聚乙二醇混合液作为蒸气源,采用单源热蒸发,在蒸发室与染料同时沉积得到混合膜,用拉曼光谱和红外光谱分析了碳膜的结构和键合方式,分析表明:碳膜中存在胺基团和氢原子.混合膜的荧光谱测量结果表明,认为正丁胺对染料荧光谱的影响是因为胺基和氢原子的存在.     

Cu0-catalysed 1,3-dipolar cycloadditions of α-amino acid derived N,N-cyclic azomethine imines to ynones

A series of 20 CuAIAC reactions between eight 4-acylamino substituted pyrazolidine-3-one-1-azomethine imines and four terminal ynones were performed using Cu⁰ as catalyst. The corresponding fluorescent cycloadducts were obtained in very high yields upon simple workup. Thus, Cu-metal turned out to be a better catalyst than Cu^I in terms of yield and ease of isolation. Availability of azomethine imines, mild reaction conditions, and simple workup enable a “click” access to libraries of densely substituted 2,3-dihydro-1H,5H-pyrazolo[1,2-a]pyrazol-1-ones. Reactivity of differently substituted dipoles was evaluated experimentally and by quantum chemical methods (DFT).     

Synthesis and antioxidative/anti-inflammatory activity of novel fullerene–polyamine conjugates

(E)-4-(Fullerenopyrrolidin-1-yl)-3-methylbut-2-enoic acid and its corresponding succinimidyl ester, readily obtained through Prato-type modification of C₆₀, were used for the selective N-acylation of polyamines. The thus obtained conjugates were evaluated for their antioxidative and anti-inflammatory activity and their cytotoxicity was determined. Members of this family of compounds showed interesting anti-lipid peroxidation, anti-lipoxygenase and anti-inflammatory activity and comparable cytocompatibility to spermidine.