甲醇、水及乙烯在氧化铌薄膜上吸附行为研究

由Nb（110）氧化制得均匀的氧化铌薄膜，用紫外光电子能谱表征了在不同温度下，甲醇、水及乙烯在该薄膜上的吸附行为．结果表明，在氧化铌表面吸附甲醇、水和乙烯，在140K时，是非解离吸附，一般由化学吸附到物理吸附．在室温时都发生解离吸附．表面缺陷位活性最强，不仅优先被吸附，而且对吸附质的影响也比较大．氧化铌薄膜表面的Nb5 是主要吸附中心，但表面气离子也是一种吸附位．     

粗糙铂电极上甲酸吸附氧化的电化学原位表面增强拉曼光谱研究

采用循环伏安法和电化学原位表面增强拉曼光谱（SERS）技术研究甲酸的解离 及附与氧化行为。首次报道了甲酸吸附、解离和氧化的电化学原位SERS谱，发现甲 酸在粗糙铂电极上能自发解离吸附；首欠成功地获得了粗糙铂电极上甲酸吸附解离 的强吸附中间体CO和活性中间体COOH的表面增强拉曼光谱，同时首次检测到甲酸氧 化最终产物CO_2的拉曼光谱信号，从分子水平证实甲酸解离吸附反应的双途径机理 。     

乙醇在粗糙铂电极上解离吸附与氧化的原位SERS研究

采用循环伏安法和原位表面增强拉曼光谱（SERS）研究了乙醇在粗糙铂电极上的吸附和氧化行为,获得了乙醇在粗糙铂电极上解离吸附的表面增强拉曼光谱.研究表明,在酸性介质中,乙醇能在粗糙铂电极上自发地解离出强吸附物种CO,在低波数区检测到桥式和线性吸附CO的铂碳键的伸缩振动信息;乙醇在粗糙铂电极上的氧化反应受扩散步骤控制;从分子水平初步证实乙醇的氧化是通过双途径机理进行的.     

激光促进甲醇氧化偶联表面反应的规律

用沉淀法制备了Ｌｉ３ＰＯ４、ＢｉＰＯ４和Ｌｉ３ＰＯ４、ＢｉＰＯ４三种固体表面材料,并用ＸＲＤ、ＩＲ、ＴＰＤ和激光促进表面反应（ＬＳＳＲ）等技术研究了这些固体表面上甲醇氧化偶联生成乙二醇的反应规律。实验结果表明：甲醇在固体材料表面的Ｐ＝９键上产生Ｃ－Ｈ端的分子态吸附,在表面的Ｌｅｗｉｓ酸位（金属离子）上产生解离态吸附。Ｌｉ３ＰＯ４和ＢｉＰＯ４的相互作用可促进甲醇在固体表面上的分子态吸附而抑制解离态吸     

CH3OH,C2H4在有序和缺陷Nb2O5表面的吸附

为了解氧化铌的表面化学，发展了不同种金属单晶底物定向生长氧化物薄膜技术以克服电子能谱研究氧化铌表面的实验困难．在超高真空系统中用ＨＲＥＥＬＳ，ＵＰＳ研究了ＣＨ３ＯＨ和Ｃ２Ｈ４在氧化铌模型表面的吸附．结果表明，ＣＨ３ＯＨ和Ｃ２Ｈ４在有序表面和缺陷表面的吸附行为表现出很大的不同，氧空穴对吸附有重要影响．     

水对甲醇在Rutile-TiO2(110)-(1 ×1)表面光催化解离的影响简

采用程序升温脱附方法研究了甲醇分子吸附在真空退火后的二氧化钛（110）表面的光催化过程,对比分析了单独吸附甲醇分子以及甲醇分子与水分子共吸附情况下的光催化解离过程. 结果表明,在二氧化钛（110）表面吸附的甲醇分子对共吸附水分子的光催化解离过程并没有直接的帮助作用. 共吸附状态下的水分子也同样没有影响到甲醇的光致解离过程,但是水分子的存在抑制了甲醇光解产物甲醛的光致脱附过程,同时促进了甲酸甲酯的形成.     

甲醇在粗糙铂电极上解离吸附的表面拉曼光谱

甲醇由于具有高能量密度及易于储存等优点，在燃料电池研究领域中备受关注．一般认为，甲醇在铂电极上的电氧化为双途径机理，即首先解离吸附在电极表面上，生成毒性中间体（CO）或活性中间体，然后再氧化生成CO。由于各研究小组使用的电极材料、预处理方法、溶液的组成以及检测手段不同，目前对甲醇的具体解离过程的细节尚未确定（如在反应条件下吸附物的特性及作用、表面结构和粗糙度的特殊影响等），还有待于建立或改进有关原位研究方法．在研究甲醇的电催化氧化的各种检测手段中，红外光谱应用得最为广泛，可用于原位红外技术中的电极…     

铂钌电极上乙醇解离吸附与氧化行为的原位SERS研究

应用电化学循环伏安法和原位表面增强拉曼光谱研究了乙醇在Pt-Ru电极上的解离吸附与氧化行为,首次获得了酸性介质中乙醇在Pt-Ru电极上解离吸附的表面拉曼光谱.实验表明:乙醇在粗糙铂和Pt-Ru电极上均能自发地解离出强吸附中间体CO,而且在Pt-Ru电极上,强吸附中间体CO氧化的过电位比在粗糙铂电极上降低了约140mV.初步证实酸性介质中乙醇在Pt-Ru电极上的氧化遵从双途径机理.本研究结果说明,表面增强拉曼光谱技术能拓展到有实用价值的电催化体系.     

Pd(510)台阶面对氢分子解离吸附的影响

本文应用对势方法构造了Ｈ２－Ｐｄ（１００）和Ｈ２－Ｐｄ（５１０）体系相互作用的ＬＥＰＳ势能面．考察了氢分子在Ｐｄ（１００）面上的非活化前驱态解离吸附特性，理论结果和实验符合得很好．对氢分子在Ｐｄ（５１０）台阶面上的解离吸附行为的研究表明，由于台阶的影响，在台阶下形成了非活化直接解离通道，在台阶上及台阶边棱处，主要存在非活化前驱态解离通道；在台阶面上发现了氢分子的活化吸附．     

乙二醇在铂电极上吸附和氧化过程的现场FTIR反射光谱研究(Ⅰ)──酸性介质

运用循环伏安法和现场FTIR反射光谱研究了酸性介质中乙二醇在铂电极上的吸附和氧化行为,指出乙二醇电催化氧化是通过解离吸附产物和反应中间体双途径机理进行的。经FTIR反射光谱检测,解离吸附产物为CO,反应中间体主要有CH₂OH─COOH和HOOC─COOH等。本文还在分子水平上解释了铂电极上乙二醇吸附和氧化循环伏安特征的内在原因。     

AMIDO- AND AMINO-ALKYLATION OF SULFIMIDES,SULFOXIMIDES, AND SULFODIIMIDES

Abstract

Sulfimides, Sulfoximides and Sulfodiimides are polyfunctional compounds with nucleophilic/basic nitrogen and acidic hydrogen adjacent to sulfur. From these Mannich-type-reaction products 1 were prepared. For example, amidomethylation on nitrogen was achieved either directly via three-component condensation (pathway (a) or, after conversion of the S-Imide into the sodium salt by treatment with N-chloromethyl-amides (pathway (b)). With highly reactive methylene-iminium halides pathway (b) provided N-aminomethylated sulfoximides, the stability of which mainly depends on the substituents on sulfur. Surprisingly stable, however, are their monoquaternary salts. These are of pharmaceutical interest with respect to anticholinergic and antihistamine activity, which was found in this series and will briefly be discussed. Of similar interest but spasmolytically less active are C-Mannich-bases of type 2 as well as N-aminoalkylated sulfodiimides 3, which were synthesized by different reaction routes.     

苯、萘、蒽芳烃分子稳定性和分子极化率规律的理论研究

苯、萘、蒽芳烃分子稳定性和分子极化率规律的理论研究桑兰芬，杨滢，杜秀华（长春光机学院基础部长春１３００１２）苏忠民，王荣顺（东北师范大学化学系长春１３００２４）关键词苯，分子极化率，同系物本文以苯、萘、蒽等最简单的单、稠环芳烃为例，对其体系稳定性变化...     

STRUCTURE,STEREOCHEMISTRY, AND MECHANISM OF FORMATION OF N-ACYLSULFILIMINES

Abstract

The methods for the preparation of sulfilimines are summarized, and the stereochemistry and electronic structure of N-acylsulfilmines are discussed. Sulfilimines have a non-planar structure, but the S^IV[sbnd]N bond character cannot be determined from their resolvability. N-Sulfonylsulfilimines (RR'SNSO₂Q) contain a delocalized S^IVNS^VI d bond system, the S^IVN and S^VIn bonds are of intermediate bond order. S^IV[sbnd]CH₃ hyperconjugation causes strong bond shortening. An asymmetric conformation of a sulfilimine containing two identical S^IV substituents was found in the crystalline state which could be accounted for theoretically. The rotation of the SN bond is not restricted in solution. The structure of N-carboacylsulfilimines (RR'SNCOQ) is strongly polar due to the strong NCO conjugation, and the instability of these compounds can be ascribed to the polar structure. The reaction between thioethers and chloramine-T is a nucleophilic substitution; the rate of the reaction is influenced by the nucleophilic character of the thioether sulfur atom. Thioether carboxylic acids are usually oxidized by chloramine-T and only give a sulfilimine if the carboxyl group is fixed sufficiently distant from the sulfur atom. The formation of sulfilimines from an optically active sulfoxide by the action of a sulfonamide (or N-sulfinylsulfonamide) proceeds via a trigonal bipyramidal intermediate with complete inversion. The intermediate of the sulfilimine synthesis starting from arylsulfonyl azides is a sulfonyl imene.     

RHEOLOCY OF AQUEOUS DISPERSIONS OF ALUMINA,TITANIA AND MIXTURE OF ALUMINA AND TITANIA POWDERS

The electrophoretic mobility and rheology of alumina, titania and alumina / titania powder mixtures ( ratio of alumina : titania 1 : 2 and 2 : 1 ) were investigated in aqueous suspensions in the pH range 3 - 10. The results suggest that the electrophoretic mobility of the individual powders is independent of the particle concentration, but the electrokinetic behavior of the powder mixture depends upon the concentration of the individual constituents. The rheology of all the suspensions is charge related and while alumina and alumina / titania ( ratio 2 : 1 ) flocculate at pH 9.0 both titania and alumina / titania ( ratio 1 : 2 ) form low viscous dispersions. Similarly while later dispersions flocculate at pH 5.6, the former dispersions behave as Newtonian type fluids. Better correlation between the slip rheology and the electrokinetic behavior of suspensions containing both alumina and titania powders can be obtained provided the experimental results are evaluated based upon the total surface area of the individual powders but not the particle concentration.     

关于二元酸与二元醇的聚酯反应和酯化与水解反应动力学

关于二元酸与二元醇的聚酯反应动力学,Flory和等人都会做过研究,唐敖庆等在较广泛的实验基础上提出氢离子催化机理及其动力学.酯化机理为:     

SYNTHESIS,REACTIONS AND BIOLOGICAL ACTIVITY OF PHOSPHORUS-CONTAINING DERIVATIVES OF CHROMONE AND COUMARIN

Chromone and coumarin derivatives exhibit a wide spectrum of biological activity, including spasmolytic, antiarrhythmic, cardiothonic, antiviral, and anticancer properties. Phosphorus-containing chromone and coumarin derivatives form a novel group of compounds, possessing remarkable cytotoxicity and alkylating and anticancer activity against selected tumor cell lines. Derivatives containing a phosphorus atom at position 2 of a γ-pyrone ring are known to be efficient antibacterial agents.

This review presents methods developed for the synthesis of derivatives of chromone and coumarin that contain a phosphonate moiety. Among them, the reaction of derivatives of 2-hydroxyacetophenone with phosphonic compounds is the one most frequently used. Some analogues were characterized by X-ray crystallography.     

丝素蛋白与聚氨酯共混膜的制备及结构和性能

采用溶液共混法制备了一系列不同组成的聚氨酯/丝素共混膜.利用红外光谱和广角X-射线衍射表征聚氨酯/丝素共混膜的结构;扫描电镜观察共混膜的断面;紫外-可见光谱测定共混膜的透光性;运用拉伸实验研究不同配比聚氨酯/丝素共混膜的力学性能.结果表明聚氨酯和丝素蛋白分子间存在较强的氢键相互作用.当丝素含量低于3 wt%时,试膜的断面较光滑,丝素蛋白分子进入聚氨酯网状结构中,破坏了聚氨酯分子内硬段和软段间的氢键作用.随着丝素含量进一步增大,丝素小颗粒均匀分散在聚氨酯基体中,二者之间具有较好的相容性.本实验所采用的制膜条件有利于促进丝素蛋白大分子的结晶.丝素蛋白对聚氨酯具有良好的增强效果,当丝素含量从0到5.6 wt%变化时,共混试片的断裂强度由0.56 MPa增大到4.60 MPa,杨氏模量由0.14 MPa增大到1.71 MPa,断裂伸长率从1065%下降到988%.丝素蛋白增强聚氨酯共混膜的强度显著增加,但弹性基本保持不变.     

苯、萘、蒽及其衍生物的荧光光谱及激发态性能的计算研究

根据Franck-Condon原理,用PPP-SC(β,γ)-CI方法在IBM-PC微机上,对苯、萘、蒽的衍生物的荧光性质以及基态和第一激发单重态在键级、偶极矩、π电子总能量上的差异进行了研究。发现最大荧光波数V~(F.L.)与荧光辐射能△F~(V.L.)、荧光量子产率φ与基态、第一激发单重态间的π电子能量差(E_g~π—E_e~π)存在着以下的关系:上述F.L.表示荧光,g表示基态,e表示激发态。由此得出的理论计算值与实验值有着良好的一致性。     

溴代聚-4-甲基戊烯-1的溶解性能及其膜的形态结构和结晶状态

<正> 迄今为止,用于气体分离的高分子膜,其气体透过速率和选择分离系数仍不够高。究其原因,一是膜材料的气体透过系数较低;二是某些气体透过系数较高的高分子材料又难以形成超薄膜层。     

9-甲基蒽单体、二聚体和夹心面包对在硅胶上的光物理和光化学性质研究

研究了在硅胶表面上的9-甲基蒽和它的二聚体及其低温光解产物(夹心面包对)的荧光光谱,激发光谱和荧光寿命。发现了一个由二聚9-甲基蒽、三氯甲烷和真空下700℃活化硅胶形成的复合物。该复合物具有与单体和二聚体不同的特征激发光谱和发射光谱,低温下光照容易分解。当分解产物缓缓加热到室温,则复合物几乎完全可以再现。二聚体低温光解产物,夹心面包对,当其缓缓加热到室温,则完全变为单体蒽。