Geometry,stability and aromaticity of β-diketiminate-coordinated alkaline-earth compounds

Alkaline-earth (Ae) metals have attracted a wealth of interdependent research from synthetic chemists. In Ae-catalyzed organometallic reactions, β-diketiminate is a typical ligand used to stabilize Ae catalysts by forming six-membered rings comprising Ae metals. Herein, studies focusing on the configuration of β-diketiminate-coordinated Ae compounds observed that the CC and CN bonds are homogeneous and unchanged. Furthermore, energetic studies observed that the formation of the Ae-incorporated six-membered rings results in enhanced stability of >20 kcal/mol. The nucleus-independent chemical shifts, anisotropy of the induced current density, and molecular orbital analyses demonstrated the non-aromaticity of the β-diketiminate-coordinated Ae compounds. The improved stability of these compounds can be explained by the delocalization of the π electrons derived from the β-diketiminate moiety.     

六甲基环三硅氧烷非平衡聚合的研究

六甲基环三硅氧烷(D_3)在为催化剂,二甲亚砜为促进剂的情况下聚合,得到了分子量分布窄且没有大环体的聚二甲基硅氧烷。本文指出了反应溶液中溶解的氧会降低催化剂的活性。在除去了溶液中的氧以后,聚合反应速度大为加快,D_3转化率几乎达100％,而且得到的聚合物是活性高分子,可以继续进行聚合。同时还研究了在除氧以后D_3非平衡聚合反应的特点。     

磺化酞菁铜分子膜／SiO2／Si界面电荷转移机制的研究

在具有不同氧化层厚度的p型硅基片上修饰2层磺化酞菁铜分子膜.利用时间分辨表面光电压谱技术,对该膜系的界面电荷转移机制的光电开关特性进行了研究。结果表明,用时间分辨表面光电压谱技术研究界面电荷转移过程具有明显优越性.     

10,12—双炔廿三酸盐的LB膜特性研究

本文合成了10,12-双炔廿三酸,并用其在Si、SiO_2、CaF_2等基片上沉积了LB膜,结果表明,10,12-双炔廿三酸的镉盐成膜更稳定。这种LB膜在紫外光辐照下很快聚合,聚合前后的紫外-可见吸收光谱发生规律性的变化,并保持层状结构,等同周期稍变。通过红外吸收的二向色性分析,确定了该分子的取向。     

JD树脂刻蚀及涂层的XPS研究

ＪＤ光学树脂表面刻蚀过程的ＸＰＳ研究表明，引进树脂遥ＣＯＨ，Ｃ＝Ｏ，Ｃ－ＳＯ３Ｈ，ＣＯＯＨ等基因随刻蚀温度的提高或时间的延长而增加，对其相对含量进行了计算，固化后的耐磨涂层具有ＳｉＯ２结构，ＪＤ板材的最佳刻蚀条件为２０℃，２０ｍｉｎ。     

Photocatalytic degradation of methylene blue on Fe3+-doped TiO2 nanoparticles under visible light irradiation

Fe³⁺-doped TiO₂ composite nanoparticles with different doping amounts were successfully synthesized using sol-gel method and characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM) and ultravioletvisible spectroscopy (UV-Vis) diffuse reflectance spectra (DRS). The photocatalytic degradation of methylene blue was used as a model reaction to evaluate the photocatalytic activity of Fe³⁺/TiO₂ nanoparticles under visible light irradiation. The influence of doping amount of Fe³⁺ (ω: 0.00%–3.00%) on photocatalytic activities of TiO₂ was investigated. Results show that the size of Fe³⁺/TiO₂ particles decreases with the increase of the amount of Fe³⁺ and their absorption spectra are broaden and absorption intensities are also increased. Doping Fe³⁺ can control the conversion of TiO₂ from anatase to rutile. The doping amount of Fe³⁺ remarkably affects the activity of the catalyst, and the optimum efficiency occurs at about the doping amount of 0.3%. The appropriate doping of Fe³⁺ can markedly increase the catalytic activity of TiO₂ under visible light irradiation. __________ Translated from Journal of Northwest Normal University (Natural Science), 2006, 42(6): 55–56 [译自: 西北师范大学学报(自然科学版)]     

反相液相色谱中固定相和流动相对柱相比的贡献

依据柱相比的热力学定义和反相液相色谱中溶质的计量置换保留理论(the stoichiometric dispheement heory of solute for retention，SDT-R)，对反相液相色谱中固定相和流动相性质、温度对柱相比的影响进行了研究。结果表明：固定相的种类和配基的疏水性对柱相比影响较大，而流动相中有机溶剂的种类，特别是脂肪酸作为置换剂时，对柱相比的影响更大，而柱相比受温度的影响较小。此外，通过用27种小分子溶质对柱相比的测定，其logI和Z良好的线性关系，进一步证明柱相比是一个与溶质性质无关的常数。     

硫化镉钠米微粒在聚合物网络中的组装

硫化镉钠米微粒在聚合物网络中的组装黄金满，杨毅，杨柏，刘式墉，沈家骢（吉林大学分子光谱与分子结构重点实验室、集成光电子国家重点实验室，长春，１３００２３）关键词组装，纳米微粒，离子交换，透射电子显微镜，电子衍射由于纳米半导体微粒的物理和化学性质介于分...     

合成多肽的电喷雾质谱研究

利用电喷雾多极串联质谱对3种合成多肽进行了系统的鉴定和分析研究。首先通过全扫描模式测定了其分子量，然后选择[M H]^ 或[M 2H]^2 离子通过串联质谱(MS／MS)得到碎片离子，采用y离子和b离子互补的方法测定了多肽序列。利用文献数据对这种方法进行了验证，实验结果表明，该方法简便、快速、实用。