苯基取代聚乙炔中的元激发

苯环取代聚乙炔是一类具有简并基态的发光聚合物.利用扩展的SuSchriefferHeeger模型,研究了这类聚合物链中的孤子、极化子等元激发特性.结果表明:由于苯环与聚乙炔主链间的强π电子耦合,苯环取代抑制了聚乙炔主链的二聚化,减小了导带与价带之间的能隙;因此取代聚乙炔中的元激发具有较小的激发能,同时具有更大的相干长度.尽管苯基取代对元激发有很大的影响,但是非取代聚乙炔中元激发的基本物理规律依然成立,表明这些元激发的基本特性不受取代基团的影响 关键词： 孤子 极化子 苯基取代聚乙炔     

CVD金刚石中的氮对等离子体刻蚀的影响

采用非对称磁镜场电子回旋共振等离子体分别对沉积过程中掺氮和未掺氮的化学气相沉积金刚石膜进行了刻蚀研究, 结果表明: 掺氮制备的金刚石膜的刻蚀主要集中在晶棱处, 经过4h刻蚀后其表面粗糙度由刻蚀前的4.761 μm下降至3.701 μm, 刻蚀对金刚石膜的表面粗糙度的影响较小; 而未掺氮制备的金刚石膜的刻蚀表现为晶面的均匀刻蚀, 晶粒坍塌,刻蚀4h后其表面粗糙度由刻蚀前的3.061 μm下降至1.083 μm. 刻蚀导致表面粗糙度显著降低. 上述差别的主要原因在于金刚石膜沉积过程中掺氮导致氮缺陷在金刚石晶棱处富集, 晶棱处电子发射加强, 引导离子向晶棱运动并产生刻蚀, 从而加剧晶棱的刻蚀. 而未掺氮金刚石膜,其缺陷相对较少且分布较均匀 ,刻蚀时整体呈现为 (111) 晶面被均匀刻蚀继而晶粒坍塌的现象. 关键词： 掺氮 金刚石膜 刻蚀 非对称磁镜场     

构建现代基础化学实验环保化导向实验课程的探讨

现代基础化学实验不可避免地会带来相应的“三废”排放问题,如何科学、环保地进行化学实验设计,最大限度地减少化学实验的污染物排放,对环境教育工作具有十分重要的意义.对现代基础化学实验设计的诸多方面进行了相应的探讨,提出了基础化学实验设计在环保方面的相关改进措施.     

具有孪晶结构的红细胞状硫化铜的制备及其光-芬顿催化性能

采用简单的溶剂热法制备出具有孪晶结构的红细胞状硫化铜材料。研究不同前驱体比例和反应时间对硫化铜产物微观形貌的影响,并对孪晶结构红细胞状硫化铜可能的形成机理进行分析。在可见光照射下孪晶结构红细胞状硫化铜与H₂O₂组成的类芬顿系统表现出优异的降解性能,光照50 min后,亚甲蓝降解率可达95%。对比孪晶结构红细胞状硫化铜与合成的花球状硫化铜的催化性能,结果表明含有孪晶结构的红细胞状硫化铜对亚甲蓝的降解性能更好,说明孪晶的存在有利于加速光生电子-空穴的分离。     

Catalytic asymmetric dipolar cycloadditions of indolyl delocalized metal-allyl species for the enantioselective synthesis of cyclopenta[b]indoles and pyrrolo[1,2-a]indoles

The development of novel synthons and efficient methods to synthesize chiral polycyclic indoles has been a hot topic in organic synthesis and medicinal chemistry owing to their broad applications in medicines, pesticides, and other functional molecules.Here, we disclosed novel indolyl substituted metal-allyl zwitterionic intermediates through the decarboxylation of conveniently available vinyl indoloxazolidones, which could be regarded as two types of dipolar species through the anionic delocalization.The palladium-π-allyl species tended to serve as an all-carbon 1,3-dipole in the asymmetric [3+2] cycloaddition with electrondeficient alkenes, which furnished polysubstituted cyclopenta[b]indoles with high regio-and stereoselectivities. Meanwhile, the iridium-π-allyl species was recognized as an aza-1,3-dipole in asymmetric [3+2] cycloaddition with in situ generated C1 ammonium enolates, affording pyrrolo[1,2-a]indoles with high diastereo-and enantioselectivities. In addition, the dipolar cycloadditions could be easily scaled-up and several synthetic transformations of the cycloadducts were demonstrated for the rapid synthesis of diverse chiral polycyclic indoles.     

Synthesis,characterization and function of ternary copper(II) complexes

Ternary complexes of glycine, alanine, -alanine, serine and ethylenediamine with copper iminodiacetate have been prepared and characterized by their i.r., u.v.-vis. and e.s.r. spectra. The data suggest that the complexes possess axial symmetry and a distorted octahedral configuration in aqueous solution. The H2O molecule on the axial copper site can be replaced by O2–. The bonding parameters, which fall between 0.84 and 0.88, indicate that the bonds between copper(II) and the ligands possess more ionic character. The ternary complex containing serine displays the highest catalytic activity in dismutation of the superoxide radical O2–. This activity may be explained on the basis of the stabilization of CuII-O2– by hydrogen bonding.     

BATPPH_2及其Zn配合物与环糊精的超分子体系研究

设计合成了5-(4-苯甲酰亚胺基苯基)-10,15,20-三苯基卟啉(BATPPH2)及其锌配合物(BATPPZn),并通过1HNMR、IR、UV-Vis、元素分析等方法对化合物的结构加以确认。在中性磷酸盐缓冲溶液中,以荧光光谱法、紫外可见分光光度法和1HNMR法分别研究了BATPPH2和BATPPZn与α,β,γ-环糊精相互作用形成的超分子体系。利用双倒数曲线法计算了BATPPH2-CD和BATPPZn-CD超分子体系的包结常数,结果表明BATPPH2和BATPPZn与γ-CD的包结常数(K1γ-CD,K2γ-CD)最大,γ-CD表现出最强的包结能力,Zn2+的配位作用使包结物的稳定性降低。     

ECR等离子体的磁电加热研究

在ECR等离子体装置上进行了磁电加热研究,利用离子灵敏探针(ISP)测量了磁电加热前后离子温度的变化,研究了电极环偏压、磁场强度、气压等参数对磁电加热过程以及加热效率的影响.结果表明:等离子体的整体加热是通过离子在电极环鞘层中的磁电加热及被加热的离子沿径向的输运来完成的.轴心处离子温度随电极环偏压的升高呈非线性增加.磁电加热效率随偏压的增大而增大,在电极环偏压为1000 V时,磁电加热效率为2%-2.5%,ECR等离子体中的离子温度能够提高20 eV以上.磁场强度在磁电加热过程中对离子的限制和加热起到重要作用,当磁场强度在6.3×10^-2-8.7×10^-2T之间变化时,磁电加热的效率随磁场强度的增大而增大.气压在0.02-0.8 Pa范围内,磁电加热的效率随气压的减小而增大. 关键词： ECR等离子体 磁电加热 离子温度     

圆筒电极对离子磁电加热的影响

高效的磁电加热不仅能够提高电子回旋共振(ECR)等离子体的离子温度,还能改善离子的径向和轴向分布,促进ECR等离子体在化学气相沉积金刚石膜刻蚀中的应用.将磁电加热系统中的圆环电极改进为圆筒电极,研究了圆筒电极对离子磁电加热的影响,对比了圆筒和圆环电极加热离子的区别.结果表明:在同一阳极偏压下,圆筒比圆环电极更有利于提高离子温度,圆筒电极加热时各径向位置的离子温度升高的幅度较大,其中圆筒电极内部的离子温度径向分布差异较大,而圆筒下游的离子温度径向分布比较均匀;磁电加热对离子密度的影响很小;采用圆筒电极加热时,有利于离子向轴向下游的输运,改善了离子的轴向均匀性.     

载Ag二氧化钛纳米管的制备及其光催化性能

Titania nanotubes (TNTs) were synthesized by hydrothermal treatment of rutile-phase TiO2 nanoparticles in 10 mol·L-1NaOHsolution at 110 ℃ for 24 h. The Ag loaded titania nanotubes (Ag/TNTs) were obtained by chemical deposition method with the TNTs suspending in the AgNO3 solution (pH=8) at 50 益. The characterizations of the as-synthesized samples were performed by TEM, EDS, XRD, XPS, and UV-Vis spectra. The photocatalytic performance of the Ag/TNTs was investigated by UV-light induced photocatalytic decomposition of methyl orange(MO). The results showed that the inner/outer diameters of TNTs were about 6/10 nm and the length was several hundred nanometers. Both the shape and the crystalline of the nanotubes were not changed after the modification. The zero oxidation state Ag quantumdots, about 4 nmin diameter, were well dispersed on the external surface of the nanotubes. Ag/TNTs exhibited enhanced absorption at the visible range in the UV-Vis spectra. The Ag nanoparticles were found to significantly enhance the photocatalytic activity of TiO2 nanotubes, and the catalyst system was demonstrated to be highly efficient for the UV-light induced photocatalytic decomposition of MO compared to both rutile-phase TiO2 nanoparticles and pure TNTs. After irradiation for 60 min, the decomposition rates of MO solution in rutile-phase TiO2 nanoparticles, TNTs, and Ag/TNTs systemwere 46.8%, 57.2%, and 92.2%, respectively.