Investigation of 1,1-diphenylethylene Oligomerization in the End-Capping Reaction of Poly(styryl)lithium

Summary: The possible oligomerization of 1,1-diphenylethylene (DPE) in the end-capping reaction of poly(styryl)lithium (PSLi) was studied in hydrocarbon solvents using excess DPE (≤16 mol-eq); the effect of addition of THF (30 mol-eq Lewis base) and extended times of reaction (8-24 h) were also investigated. The characterization of the polymers was made by size exclusion chromatography (SEC), proton nuclear magnetic resonance spectroscopy (1H NMR) and matrix-assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF MS). MALDI- TOF mass spectrometric results revealed the absence of DPE oligomerization under the reaction conditions used in this study.     

基于随机振荡序列的GM(1,1)模型性质及其应用

为了提高GM(1,1)模型对随机振荡序列的拟合和预测效果,提出了先将原始振荡序列变为单调增长序列,再对单调增长序列进行几何平均生成交换,然后建立GM(1,1)模型.通过实例计算表明,方法能够提高GM(1,1)模型的拟合精度,可以用于随机振荡序列的建模,从而扩大了GM(1,1)模型的应用范围.     

基于灰色预测模型的新疆肺结核疫情分析

借助灰色系统理论对新疆2004-2010年肺结核发病率进行研究,建立不同维度的静态GM(1,1)模型与动态等维递补灰预测模型对数据进行模拟和预测.针对新疆肺结核疫情发病率数据,探索建立新疆肺结核疫情传播预测模型,为肺结核防治提供科学依据.     

基于残差修正的非等时距GM(1,1)模型及其应用

针对很多预测案例中历史数据序列非等时距的特点,构建了非等时距的GM(1,1)预测模型,将序列的时间间隔作为乘子嵌入模型中,同时通过动态采用最新分量作为初始值、动态优化背景值和累积残差修正等方法,解决了非等时距预测模型长期预测精度不易控制的难题.将该模型应用于某发动机油液监测数据预测中,预测效果较好.     

一类含联二萘结构的新型聚芳醚酮类刚性大环及其二聚体的合成与表征

通过一定的分子设计,利用一种全新的双酚单体(4-氯代苯基对苯二酚)和含有联二萘结构的双氟三聚体(BNDIF)经一步法合成环状齐聚物,制得了一类含有氯代苯基侧基和联二萘结构的新型聚芳醚酮类刚性大环;并通过氯苯基的催化偶联反应得到了该类刚性大环的二聚体(一类含有2个联二萘结构的新型结构双环齐聚物).利用MALDI-TOFMS和1HNMR及H-HCOSY分析,证明了目标产物的结构.     

分子印迹整体柱在高效液相色谱和电色谱手性分离中的应用

在常规不锈钢色谱管中以甲基丙烯酸为功能单体,采用原位聚合法制备了(5S,11S)-特罗格尔碱(S-TB)的印迹整体柱。考察了流动相中添加不同量的醋酸和水对分离的影响,结合台阶梯度洗脱模式在S-TB整体柱上实现了对TB消旋体的快速分离。另外,以碱性单体2-二甲基乙基胺甲基丙烯酸酯(DAMA)为功能单体,在毛细管中采用原位聚合法制备了毛细管分子印迹整体柱,用于在毛细管电色谱（CEC）中对消旋体1,1′-联-2-萘酚(BNL)进行手性分离。结果表明,以AMA为功能单体可以制备其他酸性模板的分子印迹聚合物,从而扩大了分子印迹聚合物MIP）在CEC分离中的应用范围。     

1,1-二氨基二硝基乙烯晶体的密度泛函理论研究

The electronic structural properties of 1,1-diamino dinitroethylene crystal have been studied by the DFT method with B3LYP function. The calculated crystal energy is -05.81 kJ/mol,which is comparable to the reference value. The frontier bands are quite flat,indicating that the molecular states are hardly perturbed by the crystalline environment. The distribution of electronic charges determines that the molecules pack through head-end to form wave-shaped layers with extensive intermolecular hydrogen bonding within the layers and ordinary van der Waals interactions between the layers. Judged by the value of band gap of 4.0 eV,it could be predicted that the conductivity of DADNE is between the semiconductor and insulator. The frontier orbital consists of atomic orbitals of C-NO2 group,indicating that there exists a stronger conjugation among the molecules and that C-NO2 is the region with high reactivity. The population of C-NO2 bond is much less than those of all the other bonds and therefore the detonation is initiated by the breakdown of this bond.     

准SU(1,1)相干态的亚泊松分布特性

数值计算显示准SU(1,1)相干态呈亚泊松分布,这是没有经典对应的量子特性.     

MethylN-(benzylsulfonyl)oxamate as a probable intermediate in the synthesis of 4-hydroxy-5-phenyl-3(2H)-isothiazolone 1,1-dioxide from phenylmethanesulfamide and dimethyl oxalate in the presence of bases

The formation of 4-hydroxy-5-phenyl-3(2H)-isothiazolone 1,1-dioxide from phenylmethanesulfamide and dimethyl oxalate under the action of bases is apparently a two-stage process involving the formation of linear methylN-(benzylsulfonyl)oxamate followed by its cyclization. A stable complex of the heterocycle with dimethylformamide was synthesized. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 2, pp. 396–398, February, 1999.     

Reaction of 1-alkynylsilanes with triallylborane—competition between 1,1- and 1,2-allylboration

The reaction of triallylborane (All₃B, 1) with various 1-alkynylsilanes of the type Me₃Si–CCR¹ [R¹=H (2a), Me (2b), Ph (2c), CC–SiMe₃ (2d), SiMe₃ (2e)], Ph₃Si–CCPh (3) MeCC–SiMe₂SiMe₂–CCMe (4) and Me₂Si(Cl)–CCPh (5) was studied. Triallylborane 1 turned out to be much more reactive than other triorganoboranes R₃B (e.g. R=Et, Ph). In the cases of 2 and 5, the products are organometallic-substituted alkenes 6 and 11, respectively, with the boryl and silyl group in cis-positions as the result of selective 1,1-allylboration (via cleavage of the Si–C bond) or mixtures of such and other alkenes 7 or 8 because of competition between 1,1- and 1,2-allylboration (the composition of these mixtures depends on the polarity of the solvent). In the case of 4, the 1,2-dihydro-1,2-disilaborepine derivative 12 is formed selectively (twofold 1,1-allylboration). The alkyne 3 did not react with 1. The products were characterised by ¹H-, ¹¹B-, ¹³C- and ²⁹Si-NMR spectroscopy.