硅胶固载化─（Lewis）酸催化剂的研究Ⅰ．硅胶固载化─四氯化钛复合物催化体系

以硅胶球为基质键合γ－ＧＯＰＳ并各接枝上具有络合功能的三种配体，邻位氨基吡啶、间酰氨基吡啶及对酰氨基吡啶，再和ＴｉＣｌ＿４络合成固载化的Ｌｅｗｉｓ酸催化剂，将这些催化剂进行缩醛、缩酮及酯化反应，有很好的催化活性，重复使用多次不失效．本文在合成此类催化剂的过程中利用热失重（ＴＧ）法及等离子光谱法（ＩＣＰ）等检测方法对合成此类催化剂的每一步进行跟踪检测，得到键合反应，开环反应及络合反应过程中的键合量，开环相量和ＴｉＣｌ＿４络合量的定量数据．对固载化催化剂表面的接枝量有所了解，从而可进一步检测此类催化剂的催化效应并得到一些启示．     

新型含氟液晶类化合物的质谱研究

本文报道66个新型含氟液晶类化合物的电子轰击电离质谱(EIMS). 66个化合物分为三个类型, 即炔醚类, 炔酯类和炔类. 并利用MS/MS联用技术和高分辨质谱(HRMS)数据研究了三种不同类型化合物的裂解机理, 并总结其规律性, 结果将有助于未知的类似化合物的结构鉴定 .     

聚-4,7-二硫杂壬基倍半硅氧烷铂配合物的合成及其对烯烃硅氢加成反应的催化性能

4,7-二硫杂壬基三甲氧基硅烷以气相法二氧化硅固载化,再与氯亚铂酸钾反应,合成了气相法二氧化硅固载的聚-4,7-二硫杂壬基倍半硅氧烷铂配合物。该配合物用量为烯烃摩尔数十万分之一时,仍能有效地催化烯烃与三乙氧基硅烷的硅氢加成反应,单程烯烃转化数可达80,000。     

有害杂草的微量元素分析

紫茎泽兰和水葫芦均属有害杂草，大规模防治的有效方法还未找到，本文分析研究了采自昆明郊区的紫茎泽兰和滇池水域的水葫芦中微量元素的含量，为进一步开发利用这两种杂草提供科学依据。     

The self-organization properties of <Emphasis Type="Italic">n</Emphasis>-dodecylammonium α-glutamate/<Emphasis Type="Italic">n</Emphasis>-C<Subscript>5</Subscript>H<Subscript>11</Subscript>OH/water system

A biocompatible surfactant-n-dodecylammonium α-glutamate (GDA) with biodegradable and biocompatible properties was synthesized, and the phase behavior and the structural properties of GDA/n-pentanol/water system was studied by small-angle X-ray diffraction, electron spin resonance, and freeze-fracture transmission electron microscopy (FF-TEM). In the ternary phase diagram of GDA/n-pentanol/water system, there exist three isotropic regions—O/W, bicontinuous, and W/O structures, and two anisotropic regions—hexagonal liquid crystal (HEX), and lamellar liquid crystal (LLC) regions. UV irradiation causes the decrease in the interlayer space, d, of lamellar liquid crystal and in the radius, r, of column aggregates of hexagonal liquid crystal, but it has little effect on the structure of O/W and W/O microemulsions.     

Immobilization and direct electrochemistry of cytochrome <Emphasis Type="BoldItalic">c</Emphasis> at a single-walled carbon nanotube-modified electrode

A single-walled carbon nanotube (SWNT)-modified electrode was fabricated and characterized by SEM and ac impedance techniques. The direct electrochemistry of cytochrome c (Cyt c), which was adsorbed on the surface of the SWNT, was studied by cyclic voltammetry. The results from cyclic voltammetry and infrared spectroscopy indicated that Cyt c remained in its original structure and did not undergo structural change after its immobilization on the SWNT. Further results demonstrated that the SWNT had promotional effects on the direct electron transfer of Cyt c and also indicated that the immobilized Cyt c retained its electrocatalytic activity to the reduction of H₂O₂. This modified electrode might be used in development of new biosensors and the biofuel cells.     

Effect of molecular structure on the solute-micelle and solute-stationary phase binding constants in micellar liquid chromatography

The effects of molecular structure on the solute-micelle and solute-stationary phase binding constants in micellar liquid chromatography (MLC) have been investigated. The following points have been observed. (1) There is quite a good linear relationship between the solute-micelle and solute-stationary phase binding constants in MLC with the cationic (CTAB) and anionic surfactants as the additives, which means that the contribution of physico-chemical properties of solutes on the solute-micelle and solute-stationary phase binding constants acts in a parallel way. (2) Good quantitative relationships between the solute-micelle and solute-stationary phase binding constants and the solvatochromic parameters have been obtained, which indicates that the distribution mechanism of the neutral solutes in MLC is determined via their molecular interactions. Both the cavity process and the hydrogen bond interaction play a very important role in the retention of neutral solutes in MLC. The contribution of the hydrogen bond interaction, especially the hydrogen donor ability of the solutes on those binding constants in anionic and cationic surfactant MLC, is determined in a different way. (3) Linear regression analysis of the solute-micelle and solute-stationary phase binding constants between the cationic and anionic surfactant MLC has been carried out. The obtained results suggest that the transfer of the non-polar solutes from the aqueous phase to the anionic and cationic surfactant micelles acts in a parallel way, but that of the polar solutes in a different way. A model of micelles with three different sites of solubilization, i.e., (1) the core of the micelle, (2) the surface of the micelle and (3) the palisade layer of the micelle, has been used to successfully explain the observed results. Finally, the retention behavior of solutes in MLC is compared with that in reversed-phase liquid chromatography (RP-LC). It has been observed that there is no difference in separation selectivity for the non-polar solutes between MLC and RP-LC; however, for the polar solutes, MLC provides a different separation selectivity compared to that in RP-LC.     

树枝形聚合物修饰的双8-羟基喹啉光物理研究

研究了树枝形聚合物修饰的双8-羟基喹啉衍生物(Gn-QMQ, n=1~3)在二氯甲烷和乙腈中的荧光猝灭过程和荧光衰减过程. 随着代数n的增加, 猝灭速率常数减小, 核心双8-羟基喹啉基团荧光寿命增长, 非辐射失活速率常数减小. 研究结果表明, 随着代数的增加, 树枝形骨架对核心基团的位点分离作用增大, 在乙腈中树枝形骨架趋于紧密构象, 具有更强的位点分离作用.     

Experimental and theoretical studies of rate coefficients for the reaction O(3P)+CH3OH at high temperatures

Rate coefficients of the reaction O((3)P) + CH(3)OH in the temperature range of 835-1777 K were determined using a diaphragmless shock tube. O atoms were generated by photolysis of SO(2) with a KrF excimer laser at 248 nm or an ArF excimer laser at 193 nm; their concentrations were monitored via atomic resonance absorption excited by emission from a microwave-discharged mixture of O(2) and He. The rate coefficients determined for the temperature range can be represented by the Arrhenius equation, k(T) = (2.29 +/- 0.18) x 10(-10) exp[-(4210 +/- 100)T] cm(3) molecule(-1) s(-1); unless otherwise noted, all the listed errors represent one standard deviation in fitting. Combination of these and previous data at lower temperature shows a non-Arrhenius behavior described as the three-parameter equation, k(T) = (2.74 +/- 0.07) x 10(-18)T(2.25 +/- 0.13) exp[-(1500 +/- 90)T] cm(3)molecule(-1) s(-1). Theoretical calculations at the Becke-3-Lee-Yang-Parr (B3LYP)6-311 + G(3df,2p) level locate three transition states. Based on the energies computed with coupled clusters singles, doubles (triples) [CCSD(T)]/6-311 + G(3df,2p)B3LYP6-311 + G(3df,2p), the rate coefficients predicted with canonical variational transition state theory with small curvature tunneling corrections agree satisfactorily with the experimental observations. The branching ratios of two accessible reaction channels forming OH + CH(2)OH (1a) and OH + CH(3)O (1b) are predicted to vary strongly with temperature. At 300 K, reaction (1a) dominates, whereas reaction (1b) becomes more important than reaction (1a) above 1700 K.