Synthesis,Structure and Luminescent Property of an Europium(Ⅲ) Coordination Polymer

A novel europium(Ⅲ) coordination polymer, [Eu3(pydc)3(SO4)(H2O)5(ox)0.5]·3H2O(1, H2 ox = oxalic acid, H2 pydc = pyridine-2,6-dicarboxylic acid), has been synthesized hydrothermally from the self-assembly of lanthanide ions(Eu3+) with the flexible oxalic acid and the rigid pyridine-2,6-dicarboxylic acid ligands, respectively. It crystallizes in the triclinic system, space group P1 with a = 11.225(4), b = 12.390(5), c = 13.752(5)A, α = 89.228(7), β = 71.142(6), γ = 75.552(6)°, Dc = 2.317 g/cm3, μ = 5.480 mm-1, F(000) = 1150, Z = 2, the final R = 0.0351 and w R = 0.0949 for 8782 observed reflections with I 2σ(I). Structural analysis reveals that complex 1 exhibits a three-dimensional metal-organic framework via π-π stacking interactions. In addition, complex 1 displays a red fluorescence emission in the solid state at room temperature, which corresponds to the 5D0 → 7F2 transition of Eu3+ ions.     

Solvent-free preparation of arylaminotetrazole derivatives using aluminum(Ⅲ) hydrogensulfate as an effective catalyst

<正>An efficient and simple method for the preparation of 5-arylamino-1H-tetrazole and 1-aryl-5-amino-1H-tetrazole derivatives is reported using aluminum(Ⅲ) hydrogensulfate(Al(HSO_4)_3) as an effective heterogeneous catalyst from secondary arylcyanamides. Generally,when the substitution in arylcyanamide is strongly electron-withdrawing the position of equilibrium would shift toward the isomer of 1-aryl-5-amino-1H-tetrazole(B) and as the electron-donating of substituent increased,the position of equilibrium is shifted toward the isomer of 5-arylamino-1H-tetrazole(A).The present methodology offers several advantages,such as excellent yields,short reaction times,easy work-up and greener conditions.     

Ruthenium(Ⅲ) chloride as an efficient catalyst for the synthesis of perimidine derivatives under mild conditions

Various biologically important perimidine derivatives have been synthesized efficiently from various ketones and naphthalene1,8-diamine by using a catalytic amount of RuC13 (1 mol%). This method is a very simple and high yielding reaction for the synthesis of perimidine derivatives.     

Diarylprolinol in an asymmetric aldol reaction of an α-alkyl-α-oxo aldehyde as an electrophile

The direct aldol reaction of an α-alkyl-α-oxo aldehyde was catalyzed by trifluoromethyl-substituted diarylprolinol 1 to afford a γ-oxo-β-hydroxy-α-substituted aldehyde in good yield with excellent anti-selectivity and excellent enantioselectivity.     

Tracking the multiple-step formation of an iron(Ⅲ) complex and its application in photodynamic therapy for breast cancer

A tandem reaction of pyridin-2-ylmethanamine(L1′) with 8-hydroxyquinoline-2-carbaldehyde(HL1) assisted by FeCl_3 was observed to give the new nitrogen heterocycle HL3(HL3=2-(imidazo[1,5-a]pyridin-3-yl)quinolin-8-ol) as its Fe(Ⅲ) complex,[Fe(L3)Cl_2](Fe1). Electrospray ionization mass spectrometry(ESI-MS) reveals its formation involves three steps:(1) coordination of both HL1 and L1′ to Fe,(2) aldehyde-amine coupling, and(3) ring closure. The results of electronic absorption spectroscopy, cyclic voltammetry, and density functional theory(DFT) calculations show the proximity of the optical transition energy to that of the excitation of ~3O_2 to ~1O_2, which prompted us to explore its application as a photosensitizer for photodynamic therapy(PDT). Photo-toxicity studies show that Fe1 exhibits the highest anti-proliferation efficiency in human breast cancer MDA-MB-231 cells under light irradiation. Moreover, studies with orthotopic models of breast cancer further expounded the anti-tumor activity of Fe1 with no significant toxicity to other organs and low retention in the body.     

Lithiumreaktionen anα-Picolinen

Ohne ZusammenfassungII. Mitteilung:W. Gruber undK. Schlögl, Mh. Chem.81, 83 (1950).     

Kekuléan benzenoids

A Kekulé structure for a benzenoid or a fullerene $\Gamma $ is a set of edges $K$ such that each vertex of $\Gamma $ is incident with exactly one edge in $K$ , i.e. a perfect matching. All fullerenes admit a Kekulé structure; however, this is not true for benzenoids. In this paper, we develop methods for deciding whether or not a given benzenoid admits a Kekulé structure by constructing Kekulé structures that have a high density of benzene rings. The benzene rings of the Kekulé structure $K$ are the faces in $\Gamma $ that have exactly three edges in $K$ . The Fries number of $\Gamma $ is the maximum number of benzene rings over all possible Kekulé structures for $\Gamma $ and the set of benzene rings giving the Fries number is called a Fries set. The Clar number is the maximum number of independent benzene rings over all possible Kekulé structures for $\Gamma $ and the set of benzene rings giving the Clar number is called a Clar set. Our method of constructing Kekulé structures for benzenoids generally gives good estimates for the Clar and Fries numbers, often the exact values.     

Synthesis,Crystal Structure and Electrochemistry Properties of an Iron(Ⅲ) Complex Based on the 3,5-Pyridinedicarboxylate and Water Ligands

Reaction of 3,5-pyridine-dicarboxylic acid(3,5-PydcH2) with iron salt in hydrothermal condition results in the formation of a three-dimensional self-assembly network formulated as [C14H14Fe2N2O12]n,and it has been structurally characterized by elemental analysis,IR spectra and X-ray diffraction.It crystallizes in the monoclinic system,space group C2/c with a=9.9633(15),b=12.0942(18),c=7.4297(11) and β=105.822o.The units of Fe2(pydc)2·2H2O are linked into a one-dimensional structure via the chelate carboxylate groups from the 3,5-pyridine-dicarboxylate.The interlayer hydrogen bonding interactions result in a three-dimensional supramolecular architecture.In the complex,the Fe(Ⅲ) ion displays a slightly distorted pentagonal bipyramidal geometry with seven coordination numbers.Cyclic-voltammetry measurement reveals the oxidation and reduction processes for the complex are quasi-reversible in nature.     

进样阀（Ⅲ）

(续上期 )　　从上述的过程中可以看出 ,当进样阀的手柄处于“取样”和“进样”之间时 ,全部的流路是完全隔断了的。阻断了流路 ,压力必然会急剧增加。因此无论是从“取样”,到“进样”,还是从“进样”到“取样”的过程 ,动作需要迅速、果断 ,否则在此过程中将造成压力骤增。过高的压力经常会冲击色谱柱柱头 ,容易造成色谱柱损坏 ,导致分离效果下降等问题的出现。若在阀内的流路上增加设计一旁路结构 ,而结构上与上述进样阀完全一致 ,就可以完全或大部分消除“取样”与“进样”之间的压力骤增现象 ,其结果如图 3所示。此种结构的阀有 Water…     

偶氮胂Ⅲ-镧(Ⅲ)褪色光度法测定蛋白质

在pH 2.5的酸性介质中, 蛋白质与偶氮胂Ⅲ-镧（Ⅲ）络合物能够相互作用, 形成超分子复合物而使溶液褪色. 最佳条件下, 在650 nm处吸光度的降低值, 与加入的牛血清白蛋白（BSA）或人血清白蛋白（HSA）、溶菌酶（Lyso）质量浓度在一定范围内呈线性关系. BSA在0.5～35 mg/L、 HAS在1～40 mg/L, 溶菌酶（Lyso） 1.7～45 mg/L, 相对标准偏差为0.82% （n=7）. 方法用于人血清总蛋白量的测定.     

检测器(Ⅲ)

（续上期）3.3氖灯的问题紫外检测器中氖灯问题是一个令人头痛的问题。现代检测器中用于启辉和维持氖灯工作的电路比较复杂，电路部分通常还要检测氖灯是否已经工作，如果没有工作，电路系统将继续启辉氖灯。图3的情况正是说明了这一现象。色谱分析中希望的出峰时间是12min左右，但如果同时还出现了4个方形峰，这4个方形峰就是电路系统连续启辉氖灯造成的（图3－a），换只新的氛灯后色谱图就正常了（图3－b）。氖灯寿命和能量又是另一个问题。通常的氖灯寿命是在1000～2000h，但是并不是绝对的。有的氖灯在使用几百小时后，检测器的噪声水平…     

Chiral Mn(Ⅲ) salen complex immobilized on imidazole-modified mesoporous material via co-condensation method as an effective catalyst for olefin epoxidation

An imidazole modified mesoporous material has been prepared through a co-condensation procedure and adopted to covalently anchor chiral Mn(Ⅲ) salen complex. The active centers in the as-synthesized catalyst were presented in the form of ionic species. The results of XRD, FTIR, DRUV-Vis, and N2 sorp-tion confirmed the successful immobilization of chiral Mn(Ⅲ) salen complex inside the channels of the modified support and the maintenance of the mesoporous structure of parent support in the immobi-lized catalys...     

Dielectric spectroscopy of an antiferroelectric liquid crystal showing an antiferroelectric–ferrielectric transition

We report the dielectric relaxation behaviour in the antiferroelectric SmC_A* and ferrielectric SmC_γ* phases of the antiferroelectric liquid crystal 4-[5-(4-octloxyphenyl)-2-pyrimidinyl]phenyl 4,4,4-trifluoro-3-(methoxyphenyl)butanoate which shows an antiferroelectric transition at around 88±0.1°C. In the SmC_A* phase, two dielectric relaxation modes have been found, namely the usual antiferroelectric Goldstone mode and another arising from molecular rotation around its short axis. In the SmC_γ* phase, one dielectric relaxation mode has been observed due to the ferrielectric Goldstone mode. Dielectric increments and relaxation frequencies of the antiferroelectric and ferrielectric phases are estimated from the fits of the Cole–Cole function of the dielectric spectrum. The dependence of the bias field in the ferrielectric phase is also discussed.     

Reaction of arylhydrazines with an α-alkynyl-carbonylic compound: an unexpected hydration reaction

The acid catalyzed reactions of three arylhydrazines with 4-phenyl-3-butynone in order to obtain the corresponding arylhydrazone were realized. The arylhydrazone reaction and an unexpected alkyne hydration reaction product were obtained when diphenylhydrazine was used. This product was identified by spectroscopic methods and X-ray diffractogram. A reaction mechanism is proposed for its formation.     

氯冉酸阴离子桥联的Nd(Ⅲ)-Nd(Ⅲ),Dy(Ⅲ)-Dy(Ⅲ)和Ho(Ⅲ)-Ho(Ⅲ)双核配合物的合成与磁性

本文合成了三个以氯冉酸阴离子为桥基的稀土双核配合物,Ln_2(Phen)_4(CA)(NCS)_4(Ln=Nd,Dy,Ho;Phen=菲咯琳;CA=氯冉酸二价阴离子).通过元素分析,红外光谱,电导,电子吸收光谱及变温(4～300K)磁化率表征了配合物,并由变温磁化率观察到的数据和理论方程通过最小二乘法拟合,得出分子内稀土离子间的相互作用参数:Z’J’=-0.79(Nd),-0.67(Dy),-0.63cm~(-1)(Ho);表明稀土离子间存在极弱的反铁磁性交换相互作用 零场分裂参数△=-0.16(Nd),-0.76(Dy),-2.55cm~(-1)(HO);g=0.618(Nd),1.739(Dy),1601(HO),拟合因子≈10~(-4)     

Fiber-optic biosensors – an overview

This article reviews progress and developments during the past five years in the field of optical fiber biosensors. Because of the expense and time constraints associated with modern laboratory analysis, there is a growing need for real-time, low-cost technology that can be used industrially, environmentally, and clinically, and to monitor food processing. Miniaturization, integrated systems, and multianalyte determination have become key aspects of sensor development and efforts in this direction will also be discussed, with some pointers to likely directions of future research in the area. The review will provide information about the analytical characteristics and applications of fiber-optic biosensors classified depending on the biorecognition element employed - enzymes, whole cells, antibodies, nucleic acids, and biomimetic polymers.     

Photoreduction of an α-Dichloroketone

We describe here a simple three step synthesis of B-santalene (1), one of the main hydrocarbons in East Indian Sandalwood oil,³ using the readily available camphene sultone (2) as a starting material. This synthesis, outlined in Figure 1, features the novel use of a sultone as a carbon activating group and involves a new desulfurization procechrre.     

Sauerstoffbestimmung an Silberoberfl?chen

Zusammenfassung Die Schwefelwasserstoffmethode zur Bestimmung von Sauerstoff in Zink, Cadmium und Blei ermöglicht die Bestimmung des Sauerstoffgehaltes an Silberoberflächen. Das auf der Oberfläche befindliche Oxyd wird nach Ag₂O + H₂S Ag₂S + H₂O umgesetzt und das gebildete Wasser mikrogravimetrisch bestimmt. Eine störende Diffusion von Sauerstoff aus dem Inneren des Metalles kann bei der Reaktionstemperatur von etwa 500° C nicht erfolgen. Gesamtsauerstoffbestimmungen wurden zur Kontrolle mit Hilfe der Wasserstoffreduktionsmethode durchgeführt.Bei einer spezifischen Oberfläche des untersuchten, drahtförmigen Silbers von 3,84 cm²/g ergab sich ein Oberflächen-Sauerstoffgehalt von 0,0013 g/m², der einer Ag₂O-Schichtdicke von 2,55 · 10^–6 mm entspricht.Herrn Prof. Dr. Justi bin ich für wertvolle Hinweise und anregende Diskussionen sowie für sein förderndes Interesse an der vorliegenden Arbeit zu großem Dank verpflichtet.