Calix [ 4 ] arene Polyaza Derivatives： Novel Effective Neutral Receptors for Cations and α-Amino Acids

IntroductionCalixarenes are one of the most important supra-molecular building blocks, which can be modified byintroducing different functional and/or structural groupsto create a specific interaction between the host and thetarget molecules, such as meta…     

人体血清中痕量铜的PAN分光光度法的测定研究

研究了用Cu2 -1-(2-吡啶偶氮)-2-萘酚(PAN)分光光度法测定人体血清中痕量铜的最佳条件。在HCl-KCl溶液介质中,十二烷基苯磺酸钠存在下,其表观摩尔吸光系数为1.42×104 L.mol-1.cm-1,Cu2 含量在0~2μg/mL范围服从比尔定律,检测限为0.5μg/dm3。操作简便、快速,该法可用于人体血清中痕量铜的测定。     

Searching for precursors to metal-metal bonded dipalladium species: a study of Pd2(4+) complexes

Reactions of Pd3(OAc)6 with lithium salts of mononegative bidentate N,N-ligands, L, of various types, such as formamidinates, benzamidinates, triazinates, and guanidinates, were investigated in a search for ways to obtain Pd2(4+) compounds that could serve as precursors to paddlewheel complexes with a metal-metal bond and a Pd2(5+) core. It was found that the reactions are complex and that either square planar mononuclear or dinuclear species may be formed depending on the reaction conditions or the method of isolation. For Pd2L4 compounds, alpha and beta isomers were sometimes obtainable. In the alpha isomer, all N,N-ligands serve as bridges, whereas in the beta isomer, two ligands bridge the Pd2(4+) unit and each of the other two chelate to a metal atom. Electrochemistry shows that the paddlewheel compounds Pd2(TolNC(H)NTol)4, Pd2(PhNC(Ph)NPh)4, and Pd2(PhNC(Ph)NPh)3(OAc) and the orthometalated complex cis-Pd2[eta2-C6H4NC(Ph)N(H)Ph]2(mu-OAc)2 have reversible oxidation waves between 0.70 and 0.92 V vs Ag/AgCl, which makes them good candidates for chemical oxidation.     

羧甲基壳聚糖/聚乙烯醇/甘油环氧树脂蛇笼型复合螯合膜的制备及对金属离子的吸附性能

以交联甘油环氧树脂交联的聚乙烯醇(PVA)为笼树脂，羧甲基壳聚糖(CCTS)为蛇树脂制备了具有蛇笼结构的复合螯合膜，研究了其对Cu^2 、Ni^2 、Pb^2 、Fe^3 、Zn^2 ，Hg”^2 、Cd^2 等金属离子的吸附性能，研究表明，该树脂对Cu^2 、Ni^2 、Pb^2 有较好的吸附性能，其中PVA是对Cu^2 的吸附的主要贡献者，而CCTS则是在对Ni^2 的吸附中起主要作用。该树脂可以用于含Cu^2 废水的处理。     

聚酰亚胺LB膜热解制备SiC薄膜的XPS研究

用XPS对沉积在硅基片上的聚酰亚胺LB膜以及由它真空热解制备的SiC薄膜进行了研究 ,并对其形成过程进行了跟踪分析 .XPS结果显示聚酰亚胺LB膜结构均匀 ,质量良好 ;真空热解时 ,约在 6 70℃时LB膜中的C与衬底Si反应形成SiC ;Ar离子溅射深度俄歇谱表明所制备的SiC膜中Si和C浓度成梯度分布 ,说明SiC是由Si和C相互扩散反应形成的     

Modifying electronic communication in dimolybdenum units by linkage isomers of bridged oxamidate dianions

Reactions of Mo(2)(O(2)CCH(3))(DAniF)(3), DAniF = N,N'-di-p-anisylformamidinate, with oxamidate dianions [ArNC(O)C(O)NAr](2-), Ar = C(6)H(5) and p-anisyl, give pairs of isomeric compounds where the [Mo(2)] units are bridged by the oxamidate anions. For the alpha isomers, the C-C unit of the dianion is nearly perpendicular to the Mo-Mo bonds, and these are essentially perpendicular to each other. For the beta isomers, the corresponding C-C unit and the Mo-Mo bonds are essentially parallel to each other. Each type of isomer is stable in solution. The electronic communication as measured by the DeltaE(1/2) for the oxidation of each of the Mo(2) units is significantly better for the beta isomers. This is supported also by the appearance of what is conventionally called an intervalence charge-transfer band in the near infrared region upon oxidation of the beta isomers but not the alpha isomers. Molecular mechanics and DFT calculations help explain the relative conformations in the alpha isomers and the relative energy differences between the alpha and beta isomers.     

Separation and determination of seven fluoroquinolones by pressurized capillary electrochromatography

In this paper, pressurized CEC was used for the separation and determination of seven fluoroquinolones (FQs). The effect of different experimental conditions, such as the concentration and pH of the buffer, the organic modifier concentration, the surfactant and ion-paring agents added to the electrolyte, and applied voltage were studied. All the seven FQs were baseline separated using mobile phase containing 27% v/v ACN, 5 mmol/L Na2HPO4 buffer (pH 4.0 adjusted using citric acid), 11 mmol/L SDS, and 0.01% TEA v/v at detection wavelength of 287 nm and at an applied voltage of -10 kV. The calibration curves were linear (r>0.9991) over a concentration range of 1.0-50.0 mg/L for norfloxacin (NFLX); 2.5-50.0 mg/L for fleroxacin (FLX), ciprofloxacin (CPFX), and lomefloxacin (LMX); and 5.0-50.0 mg/L for enoxacin (ENX), ofloxacin (OFLX), and gatifloxacin (GFLX). The detection limits (S/N = 3) for ENX, OFLX, FLX, NFLX, CPFX, LMX, and GFLX were 0.5, 0.8, 0.4, 0.2, 0.4, 0.5, and 1.0 mg/L, respectively. The method is simple, rapid, and reproducible. It was successfully applied to the analysis of fish muscle samples spiked with FQs. Mean recoveries ranged from 81.6 to 97.6%.     

Trapping tetramethoxyzincate and -cobaltate(II) between Mo24+ units

Two compounds of a new type, [Mo(2)](CH(3)O)(2)M(CH(3)O)(2)[Mo(2)] where [Mo(2)] is an abbreviation for Mo(2)[(p-MeOC(6)H(4))NCHN(p-MeOC(6)H(4))](3) and M = Zn (1) and Co (2), are reported. Discrete [M(OR)(4)](2-) ions, either as such or in the mu(2),eta(4) role, have not heretofore been described. In these compounds they have distorted tetrahedral structures and bridge two [Mo(2)] groups in much the same way as did SO(4)(2-), MoO(4)(2-), and WO(4)(2-) ions in other recently reported compounds (Cotton, F. A.; Donahue, J. P.; Murillo, C. A. Inorg. Chem. 2001, 40, 2229). The (1)H NMR spectrum of 1 and the visible spectrum and magnetic properties of 2 are consistent with these structures. The M(OCH(3))(4) bridges are moderately effective in coupling the two [Mo(2)] redox centers. Compounds 1 and 2 may also be viewed as having Zn(II) and Co(II) centers tetrahedrally coordinated by the bidentate ligand [Mo(2)[(p-MeOC(6)H(4))NCHN(p-MeOC(6)H(4))](3)(OMe)(2)](-). From that point of view they may be compared with Zn(DPM)(2) and Co(DPM)(2) (3), where DPM is the anion of dipivaloylmethane. For purposes of comparison, 3 has been fully characterized structurally, spectroscopically, and magnetically. Close analogies between 2 and 3 are shown to exist.     

Clean Aerobic Liquid Oxidation of Aldehydes with Solid Catalyst

Clean liquid oxidation of aldehydes can be accomplished using solid catalyst in the presence of molecular oxygen at room temperature, which is a valuable alternative to traditional counterparts.     

Synthesis and Crystal Structure of 1,7,7-Trimethyl- 4-（4-methoxyphenyl）-4,6,7,8-tetrahydroquinoline- 2,5（1H,3H）-diones under Microwave Irradiation

1 INTRODUCTION Various quinolone derivatives are known to dis- play interesting biological properties ranging from microbial activity to cytotoxicity[1]. They have been reported as antiviral (HIV-1)[2] and antitumor agents[3] as well as used as tubulin[4], topoisomerase[5] and thrombocyte inhibitors[6]. As a member of the quino- lone family, substituted N-phenyl-2-quinolones re-present the structural basis of many biologically active compounds, such as protein kinase inhibitors, immunodu…