吲哚-9,10-二甲氧基蒽体系分子内能量转移反应的研究

本文分别用亚甲基和甾体雌二醇刚性链将吲哚与9,10-二甲氧基蒽连接起来,合成了两个分子内能量转移体系,研究了分子內吲哚的激发能向9,10-二甲氧基蒽的传递过程与距离及溶剂环境的关系;发现在两个体系中激发吲哚都可以发生从吲哚到9,10-二甲氧基蒽的单重态-单重态能量转移,在远距离的条件下,能量转移按偶极子-偶极子共振机制进行,由实验结果,根据Forster公式计算得到的给体与受体之间的距离与用分子模型测量得到的距离是一样的,并研究了溶剂极性对能量转移过程的影响。     

Side chain liquid crystal polyurethanes with azobenzene mesogenic moieties: Influence of spacer length on hydrogen bonding at different temperatures

A series of side chain liquid crystal polyurethanes (CnCNPs), in which the spacer length was varied from 2 to 12 methylene units, were synthesized by the addition polymerization of α-[bis(2-hydroxyethyl)amino]-ω-(4-cyanoazobenzene-4′-oxy)alkanes (CnCN-diols) with hexamethylene diisocyanate. The liquid crystalline properties of CnCNPs were characterized by means of differential scanning calorimetry, polarizing optical microscopy, and X-ray diffraction. Polyurethanes with spacer length 4 or higher exhibited mesomophic properties. C4CNP and C5CNP exhibited an enantiotropic nematic mesophase, while C6-C12CNPs exhibited enantiotropic bilayer smectic mesophases. CnCNPs have a high tendency to crystallize; crystallization is kinetically controlled. Polyurethane's backbone crystallization is closely related to hydrogen bonding. To establish the role of hydrogen bonding in mesophase formation as well as crystallization, Fourier transform infrared spectroscopy studies of CnCNPs were carried out at different temperatures focusing on H-bonds between the N H and CO groups of the urethane backbone. With increasing temperature, CO and N H stretching bands were evenly shifted to higher wavenumbers, with two exceptions (C4CNP and C5CNP) discussed in detail in the text. © 1998 John Wiley & Sons, Inc. J. Polym. Sci. A Polym. Chem. 36: 2135–2146, 1998     

New macroporous polymers for the selective adsorption of gold (III) and palladium (II). I. The synthesis,characterization, and effect of spacers on metal adsorption

New macroporous polymers with a functional group based on triisobutylphosphine sulphide are synthesized and characterized for the selective adsorption of gold and palladium. Five coordinating polymers are prepared from chloromethylated divinylbenzene polystyrene, by either direct attachement of the phosphine sulphide to the polymer or through a spacer chain that is modified to introduce O and S heteroatoms. The influence of the length and composition of the spacer chain on resin capacities is studied. The presence of O and S heteroatoms in the spacer increases the hydrophilicity of the polymers, and it is found to be essential for the adsorption of Au(III) and Pd(II). This is attributed to the coordination of the metal with the heteroatoms of the spacer. © 2000 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 38: 269–278, 2000     

有机分子隔离层对机械抛光金属银表面的罗丹明6G荧光增强效应的影响

采用物理吸附法,在机械抛光纯银表面引入对巯基苯胺(p-Amiothiophenol,PATP)分子充当隔离层,运用激光光谱学方法研究隔离层对位于银表面附近的罗丹明6G(Rh6G)分子的荧光增强效应影响。实验结果表明,未经PATP分子修饰的机械抛光金属衬底对Rh6G分子表现为猝灭效应,而经过PATP分子修饰后的银表面对Rh6G分子的荧光发射具有增强效应。根据局域表面等离子共振及辐射能量转移模型对实验观测所得结果进行了分析研究,结果表明,PATP有机分子隔离层的引入有效地减小了荧光分子与金属衬底之间的无辐射能量速率,提高了荧光辐射强度。     

Spacer layer thickness fluctuation scattering in a modulation-doped Al_xGa_1-xAs/GaAs/Al_xGa_1-xAs quantum well

We theoretically study the influence of spacer layer thickness fluctuation(SLTF) on the mobility of a twodimensional electron gas(2DEG) in the modulation-doped Al x Ga 1 x As/GaAs/Al x Ga 1 x As quantum well.The dependence of the mobility limited by SLTF scattering on spacer layer thickness and donor density are obtained.The results show that SLTF scattering is an important scattering mechanism for the quantum well structure with a thick well layer.     

Resonance Raman Scattering of Undoped Trans-Polyacetylene in the Region of the Absorption Edge

Resonance Ranan Scattering of undoped CH)_X was studied for excitation wavelength λ_L between 700 and 1064 nm. Scattering is entirely due to long conjugated chains, but with evidence of disorder. Positions and shapes of the Raman lines are studied as a function of λ_L. The action spectrum shows a maximm near 1.4 eV, with a width > 0.2 eV at 2 K and no other structure.     

TiO2光学间隔层增强聚合物太阳能电池光吸收的分析

基于共轭聚合物给体材料聚3-己基噻吩（P3HT）和富勒烯衍生物受体材料（6,6）-苯基-C61（PCBM）共混的体异质结结构的聚合物太阳能电池因其空穴载流子迁移率低而限制了P3HT:PCBM功能层厚度,从而影响了器件对入射光的吸收、在聚合物功能层和反射电极间插入TiO₂光学间隔层可以使器件内电场重新分布并改善器件的光吸收.基于薄膜传递矩阵法计算了不同的P3HT:PCBM功能层厚度和TiO₂插入层厚度的器件内光电场和光吸收.理论分析证明:器件结构为铟锡氧化物（ITO）（100 nm）/聚3,4-乙撑二氧噻吩/聚苯乙烯磺酸盐PEDOT:PSS（40 nm）/P3HT:PCBM/TiO₂/LiF（1 nm）/Al（120 nm）时,插入10 nm厚的TiO₂膜层可以使器件的聚合物功能层厚度在减薄25 nm的同时增加16.3%的光子吸收数,并且不明显降低功能层的激子分离概率,即功能层和TiO₂光学间隔层厚度分别约为75和10 nm时的器件性能为宜,此结果通过器件性能实验得以证实.     

Synthesis and Properties of Gemini Cationic Surfactants with Amide Spacers

Four gemini cationic surfactants {N,N‘-di[2-(lauryldimethylamino)acetyl]polymethylenediamine dichloride, LAA-s-LAA, s = 2,3,4,6 } were synthesized by using four bis (a-chloroacetamide)s and N, N-dimethyl-laurylamine, respectively. The molecular structures were characterized by means of IR, ^1H NMR. ^13C NMR and MS, and the behavior of their aqueous solutions was studied. The critical micell concentrations (CMC) of LAA-s-LAA were one order of magnitude lower than that of dodecyltrimethyl ammonium chloride (DTAC). With the change of the length of spacer chain(s), their CMC values change, and CMC reaches the top value at s=4.