Copper‐Catalyzed Electrophilic Cyclization of N‐Propargylamines with Sodium Sulfinate for the Synthesis of 3‐Sulfonated Quinolines

A convenient and effective protocol for the synthesis of 3‐sulfonated quinolines via copper‐catalyzed electrophilic cyclization of N‐propargylamines has been developed, in which cheap and stable sodium sulfinates were utilized as green sulfonylation reagents. This cascade transformation involves radical addition, cyclization and dehydrogenative aromatization processes in a one‐pot reaction under mild conditions.     

Phosphine‐Catalyzed (3+2) Annulation of Isoindigos with Allenes: Enantioselective Formation of Two Vicinal Quaternary Stereogenic Centers

Construction of contiguous all‐carbon quaternary stereogenic centers is a long‐standing challenge in synthetic organic chemistry. In this report, a phosphine‐catalyzed enantioselective (3+2) annulation reaction between allenes and isoindigos, containing either two identical or different oxindole moieties, is introduced as a powerful strategy for the construction of spirocyclic bisindoline alkaloid core structures. The reported reactions feature high chemical yields, excellent enantioselectivities, and very good regioselectivities, and are highly useful for creating structurally challenging bisindoline natural products.     

具有螺旋结构的金属镍有机-无机配位聚合物的合成及表征

在水热体系中合成了3个中心金属为镍离子, 以六配位扭曲八面体构型形成的具有螺旋结构的配位聚合物{[Ni₂L₂(bib)₂·2H₂O]·5H₂O}_n(1), [Ni₂L₂(bpy)]_n(2)和{[Ni₂L₂(bibpip)₂·2H₂O]·6H₂O}_n(3)[H₂L=4,4'-三苯胺二甲酸; bib=1,3-二(咪唑基)苯; bpy=4,4-联吡啶; bibpip=1,4-二(4-咪唑苄基)哌嗪]. 通过单晶及粉末X射线衍射、 红外光谱、 元素分析和热重分析对这3种化合物进行了表征. 结果表明, 化合物1属于单斜晶系, C2/c空间群, 其骨架为具有{4²·6⁵·8}拓扑结构的二维层结构; 化合物2属于斜方晶系, Fdd2空间群, 其骨架为具有{4⁸·5⁴·6³}拓扑结构的三维超分子网络; 化合物3属于三斜晶系, P\begin{array}{c}\bar{1}\end{array}空间群, 为1个五重穿插的三维超分子网络, 其骨架具有{4⁴·6²}拓扑结构.     

A Model for Extreme Ultraviolet Radiation Conversion Efficiency From Laser Produced Mass-Limited Tin-Based Droplet Target Plasmas

Simple arguments are used to construct a model to explain the extreme ultraviolet radiation conversion efficiency(EUV-CE) of a tin-based droplet target laser produced plasmas by calculating the laser absorption efficiency,radiation efficiency,and spectral efficiency.The dependence of drive laser pulse duration and laser intensity on EUV-CE is investigated.The results show that at some appropriate laser intensity,where the sum energy of the thermal conduction,out-off band radiation and plasma plume kinetic losses is at a minimum,the EUV-CE should reach a maximum.The EUV-CE predicted by the present simple model is also compared with the available experimental and simulation data and a fair agreement between them is found.     

稻瘟病、玉米锈病和蚕豆锈病叶的傅里叶变换红外光谱研究

利用傅里叶变换红外光谱(FTIR)研究了水稻、玉米、蚕豆正常叶和稻瘟病叶、玉米和蚕豆锈病叶。结果显示,其红外光谱均主要由多糖、蛋白质的振动吸收谱带组成。光谱整体相似,差异主要表现为光谱峰位、峰形及吸收强度比。三种作物正常叶的二阶导数光谱在1 750～1 500 cm-1范围内的相关系数差异明显。水稻正常叶与稻瘟病叶的吸收强度比A_{1 056}/A_{1 652};蚕豆正常叶与锈病叶的吸收强度比A_{1 652}/A_{2 920};玉米正常叶和锈病叶(非病斑部位)吸收强度比A_{1 056}/A_{2 920},玉米正常叶和玉米锈病叶(病斑处)吸收强度比A_{1 652}/A_{2 920},均呈现出病变叶吸收强度比正常叶要小的趋势。表明他们之间的多糖和蛋白质的含量存在差异。     

The method of quasi-reversibility to solve the Cauchy problems for elliptic partial differential equations

We use the method of quasi-reversibility, first introduced in [1], to solve the ill-posed Cauchy problems for an elliptic operator such as P = –Δ. In particular, a non-conforming method is implemented, some a priori error estimates are derived, and a few numerical computations are presented. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)     

荧光光谱滴定法研究葫芦脲[7]对亚甲基蓝的包结作用

采用荧光光谱滴定法研究了不同温度下及醋酸缓冲溶液中,葫芦脲[7](CB7)对亚甲基蓝(MB)的包结作用。在一定的浓度范围内,体系的荧光强度随着CB7浓度的增大而增强,且荧光峰位有一定的蓝移,结果显示二者形成了1∶1的包结配合物,同时计算了它们的包结稳定常数以及相关热力学常数ΔG,Δh和ΔS,热力学常数数值说明反应是焓变驱动的。此外,利用1H NMR谱图,结合葫芦脲[7]以及客体亚甲基蓝的结构特征,对其包结机理及主客体作用模式进行了探讨。     

Covalent Interaction of Ru(terpy)(tmephen)Cl+ with DNA: A Potential Ruthenium‐Based Anticancer Drug

The use of ruthenium complexes in antitumor therapy was launched two decades ago. In view of their low toxicity and good selectivity for solid tumor metastasis, ruthenium complexes have great potential as alternative drugs to cisplatin in cancer chemotherapy. A series of monochloro ruthenium complexes, Ru(terpy) (NN)Cl⁺ (NN, bidentate nitrogen ligand), containing different electron‐donating groups were prepared. The reactivity towards the formation of Ru‐DNA adduct were revealed by gel mobility shift assay. Their DNA binding sites of Ru(terpy)(tmephen)Cl⁺ were located predominantly at the purine residues i.e., guanine and adenine, by terminating DNA elongation in vitro using PCR and primer extension techniques. Surprisingly, the ability of Ru(terpy)(tmephen)Cl⁺ to inhibit cell growth was found to be approximately two times better than that of a known cross‐linking agent, Ru(bpy)₂Cl₂. Therefore, the increase in liability of the chloro ligand was demonstrated to improve the reactivity of these ruthenium complexes towards the covalent bond formation in Ru‐DNA adducts and result also in a significant inhibition of cell growth. Based on our results, these ruthenium complexes modified with electron‐rich groups provide new consideration in the tune of ruthenium‐based drugs in cancer chemotherapy.     

CdS/PPA纳米溶胶荧光探针同步荧光光度法测定水溶液中牛血清白蛋白

同步荧光光谱;CdS/PPA纳米粒子;牛血清白蛋白     

以石墨烯为电极的有机噻吩分子整流器的设计及电输运特性研究

传统硅基半导体器件受到了量子尺寸效应的限制,发展分子电子学器件有可能解决这一难题.本文提出了由石墨烯电极和有机噻吩分子相结合构造分子器件的思想,建构了"石墨烯-噻吩分子-石墨烯"结构的分子器件,并运用非平衡态格林函数结合密度泛函理论的方法研究了其电输运特性.系统地分析了电子给体"氨基"和电子受体"硝基"两种取代基的位置对有机噻吩分子电输运的影响.计算表明,有机噻吩二聚物被"氨基"和"硝基"取代后会产生明显的负微分电阻效应和整流效应.进一步对产生这些效应的物理机制进行分析,发现氨基的位置可以调整负微分电阻的强弱,硝基的位置可以改变整流的方向.