柔红霉素与DNA相互作用的机理研究

本文以循环伏安、光谱电化学和原子力显微镜方法从DNA角度研究柔红霉素与天然鱼精DNA和热变性DNA之间相互作用的机理。并对柔红霉素与鱼精DNA和热变性DNA复合物的组成及复合物的形成常数作了测定。研究发现嵌入作用是柔红霉素和天然DNA之间的主要作用方式；并且柔红霉素和天然DNA之间的作用要强于和热变性单链DNA之间的作用。对这两种复合物的光谱电化学和原子力显微镜研究表明，在体内氧化还原代谢条件下，柔红霉素还原过程中产生的半醌自由基可引发自由基链反应，造成DNA链的解链、断裂等损伤。     

Microcalorimetric Studies of the Toxic Action of La^3＋ on Halobacterium Halobium R1 Growth

A microcalorimetric technique was used to evaluate the influence of La^3 on Halobacterium halobium R1 growth.By means of LKB-2277 bioactivity monitor,ampoule methos at 37℃,the thermogenic curves of Halobacterium halobium R1 growth were obtained.In order to analyze the results,the maximum power Pm and the growth rate constants k were determined,showing that values of Pm and k are linked to the concentration of La^3 .Addition of low concentration of La^3 can cause a decrease of the maximum heat production and growth rate constant.However,high concentration of La^3 may promote growth of Halobacterium halobium R1,but at much higher concentration of La^3 ,the growth of Halobacterium halobium R1 is inhibited again.For comparison,the shapes of Halobacterium halobium R1 cell were observed by means of transmission electron microscope.According to the thermogenic curves and TEM photos of Halobacterium halobium R1 under different conditions,it is clear that metabolic mechanism of Halobacterium halobium R1 growth is changed with the addition of La^3 .     

Novel Monomeric Phenanthroline - Thallium(III) Complexes Multinuclear NMR Characterization in Organic Solvents

Thallium(III) complexes with nitrogen donor ligands constitute an interesting field in coordination chemistry. Phenanthroline is an extremely stiff organic ligand. The stability constants of its coordination compounds with Tl(III) have been investigated in aqueous solution by potentiometer1. 205Tl NMR technique has provided an effective method to study the thallium(III) solution chemistry. Thallium(III) coordination chemistry has attracted considerable attention recently for its ric…     

两亲8-氨基喹啉衍生物的空穴传输特性及LB膜电致发光器件

在过去的20年里,电致发光(EL)领域的研究显得异常活跃,EL已应用于通讯、信息、显示等许多领域,而占领这一领域的是P-N结无机半导体发光二级管,其发光效率已超过了白炽灯.但由于无机半导体很难实现大面积平面显示,加之成本较高,因此,限制了其进一步的发展[1].有机荧光材料的种类繁多,荧光量子效率高,且可以通过分子结构修饰有目的地控制其发光效率、发光颜色和电学性能[2],因而,越来越多的学术界和工业界的研究小组进入了有机电致发光研究领域[3.4].     

用定量结构性质关系预测表面活性剂的浊点

用结构、电子、空间和热力学等性质为描述符，建立了宏观性质非离子表面活性剂浊点与微观结构之间的定量结构性质关系. 这些描述符包括辛醇/水分配系数lgP、分子表面积A、相对分子质量Mr、偶极矩μ-y和μ-z.通过49个非离子表面活性剂浊点的实验数值与五个性质之间的关系式，成功地预测了其他非离子表面活性剂的浊点.     

微电渗流毛细管原位柱的制备及性能考察

 采用二元致孔剂原位聚合的方法制备了一种新型微电渗流毛细管原位柱。与三元致孔剂制柱方法相比 ,具有制备过程简单、重复性好、能够方便地通过改变致孔剂配比来改变柱床的孔径和孔结构的特点。得到的毛细管柱内部结构均匀 ,通透性好。通过对改变不同致孔剂配比所制备的原位柱的孔结构特征及电渗流情况考察 ,及对柱长和柱径与电渗流的关系的探讨 ,发现制备的原位柱在较高 pH值和较高的有机改性剂浓度条件下 ,电渗流均能保持在较低值 ,可以适应不同电泳分离模式的需要。     

A highly pi-stacked organic semiconductor for field-effect transistors based on linearly condensed pentathienoacene

We present the synthesis and characterization of a fused-ring compound, dithieno[2,3-d:2',3'-d']thieno[3,2-b:4,5-b']dithiophene (pentathienoacene, PTA). In contrast to pentacene, PTA has a larger band gap than most semiconductors used in organic field-effect transistors (OFETs) and therefore is expected to be stable in air. The large pi-conjugated and planar molecular structure of PTA would also form higher molecular orders that are conductive for carrier transport. X-ray diffraction and atomic force microscopy experiments on its films show that the molecules stack in layers with their long axis upright from the surface. X-ray photoelectron spectroscopy suggests that there are no chemical bonds at the PTA/Au interface. OFETs based on the PTA have been constructed, and their performances as p-type semiconductors are also presented. A high mobility of 0.045 cm(2)/V s and an on/off ratio of 10(3) for a PTA OFET have been achieved, demonstrating the potential of PTA for application in future organic electronics.     

Synthesis of heterocycle‐substituted pyropheophorbide derivatives

Methyl pyropheophorbide‐a (MPPa) ( 1 ) was converted to two aldehydes, methyl 2‐formylmethyl‐2‐devinylpyropheophorbide‐a ( 2 ) and methyl 2‐formyl‐2‐devinylpyropheophorbide‐a ( 3 ). The former 2 reacted with active methylene compounds having a cyano function in the presence of sulfur to afford thiophene‐substituted chlorins 5a‐c and reacted with arylhydrazines to yield indole‐substituted chlorins 6a‐d . From the latter 3 , a α‐diketo chlorin 7 was obtained via Wittig reaction and oxidation. Compound 7 reacted with o‐phenylenediamine to afford 2‐quinoxalyl‐substituted pyropheophorbide‐a 8. The reaction of MPPa ( 1 ) with anthranilamide to give a spiro‐substituted compound 9 .     

Poly[[[aqua­(2,2′‐bipyridine‐κ2N,N′)manganese(II)]‐μ3‐acetyl­enedicarboxylato‐κ3O:O′:O′′] monohydrate]

In the title complex, {[Mn(C₄O₄)(C₁₀H₈N₂)(H₂O)]·H₂O}_n, each Mn^II ion has a distorted octa­hedral coordination formed by two N atoms of a 2,2′‐bipyridine ligand, three carboxyl O atoms of three different acetyl­ene­dicarboxyl­ate ligands and one coordinated water mol­ecule. The acetyl­ene­dicarboxyl­ate ligands act in a tridentate mode connecting adjacent Mn^II ions and constructing a two‐dimensional structure which can be regarded as an unusual plywood‐like stacked network.