The Interaction of Co(II), Ni(II), Cu(II), Zn(II), and Cd(II) with Mixed Donor Macrocycles Containing Pendant Carboxylic Acid Functions

The syntheses of mixed oxygen-nitrogen donor macrocycles incorporating two or three pendant carboxylic acid groups are described. Potentiometric titrations in water (I = 0.1; KNO₃) at 25°C have been used to determine the stability constants for the 1: 1 (metal:ligand) complexes of Co(II). Ni(II), Cu(II), Zn(II), and Cd(II). The constants obtained are compared with the previously determined values for the corresponding complexes of the unsubstituted macrocyclic precursors. The results of these studies indicate that each carboxylate function participates in binding to the central metal. For some metal-ion/ligand systems there is evidence that ring size effects influence the overall stability patterns and that, in such cases, both the ether oxygens as well as the tertiary amines of the macrocyclic rings appear to bind to the metal.     

New Macrocycles Containing the Azoxy Subunit and Their Properties

Abstract

A new macroring closure reaction leading to crown-like macrocycles containing the azoxy group as a new macroring subunit has been introduced. The possibility of complex formation with cations has been examined by studying these compounds in membrane ion-selective electrodes.     

REACTIONS OF TRIMETHYL GROUP IVA HALIDES (Si,Ge, Sn) WITH PHOSPHINE-BRIDGED PALLADIUM,PLATINUM, AND SILVER DIMERS

Abstract

Reactions of a series of binuclear, phosphine bridged late transition metal complexes, Pd₂Cl₂(dppm)₂, Pd₂Cl₂(dmpm)₂, Pd₂Cl₂(Ph₂Ppy)₂, Pt₂Cl₂(dppm)₂, and Ag₂Br₂(dppm)₂, with Me₃SiX (X = Br, I), Me₃GeBr and Me₃SnBr were examined by ³¹P NMR spectroscopy. Rapid exchange of Pd-Cl, Pt-Cl and Ag-Br bonds for Pd-X, Pt-X (X = Br, I) and Ag-I bonds was observed to be independent of the nature of the phosphine ligand, the nature of the metal center or the group IV element. Differences in Lewis acidity of the transition metal center as a function of the ligands and the identity of the transition metal and differences in the basicity of the Me₃EBr ligands are proposed to account for the failure to detect intermediates in these reactions similar to those reported for reactions between Pd₂Cl₂(dppm)₂ and Me₃SiX.     

含羧基交联型质子交换膜的制备及其性能

合成了一种含酯基的磺化聚合物,利用后水解的方法得到了含有羧基侧基的聚合物;将磺化聚合物与聚乙烯醇通过溶液共混,热处理后得到交联型的共混膜材料。 研究结果表明,膜材料的玻璃化转变温度(Tg)有明显的上升,证明了交联反应的发生;同时,膜的吸水率和溶胀率有一定的下降,力学性能和热稳定性也有一定的提升。 通过共价交联的方法,制备了综合性能优异的磺化聚芳醚质子交换膜材料。 在100 ℃,交联膜的质子传导率为0.072~0.065 S/cm,吸水率为51%~89%,溶胀率为19%~30%。     

官能团修饰对MOF-5的气体分子吸附影响

采用紧束缚近似计算方法,研究了金属有机骨架(MOF-5)和不同官能团(―NO2,―NH2,―CH3,―OZn)修饰后的MOF-5不同吸附位点的CO2等温室气体和部分工业废气吸附性能以及对不同气体的选择性吸附能力.结果表明,对于未修饰的MOF-5,位点I和II是主要的吸附位点,最大吸附能可达-0.25eV.官能团修饰提高了MOF-5对CO2的吸附能力,其与官能团活性和局部位型密切相关.其中―NO2修饰使各位点的CO2吸附能力都有一定提高.同时,―NO2修饰后MOF-5对空气环境(O2,N2,H2O,CO2),工业废气环境(CO2,CO,NO,NO2,SO2,SO3)中不同气体有明显的选择性吸附能力.     

Modification of Interfacial Interaction of PBT/PP Blends by Adding Main-chain Liquid Crystalline Ionomer with Sulfonic Group

A main-chain liquid crystalline ionomer(MLCI)containing sulfonic group was synthesized by an interfacial condensation reaction.The MLCI was blended with polybutylene terephthalate(PBT)and polypropylene...     

基于巯基点击反应与RAFT聚合的功能性聚合物合成

可逆加成-裂解链转移聚合(RAFT)由于单体适用面广、聚合条件温和、不受聚合方法的限制等特性, 已经成为活性合成聚合物的有效手段之一。点击化学(click chemistry)由于具有良好的选择性、模块性以及官能团耐受性等特点迅速成为许多研究领域,如药物、聚合物、功能材料等合成的有力工具,同时涌现出了多种基于巯基的点击反应。本文综述了近年来基于巯基的点击反应, 如巯基-烯、巯基-炔、巯基-异氰酸酯、巯基-环氧化物以及巯基-卤代烃等新型点击反应与RAFT聚合相结合在功能性聚合物的制备和修饰中的应用, 相信这两种手段的结合将在其中发挥积极的作用。     

Synthesis, Structure and Properties of a Strontium（Ⅱ） Complex with 2, 3-Pyrazinedicarboxylic Acid

Complex [Sr2(pdc)2(H2O)7]·H2O(1, H2 pdc=2,3-pyrazinedicarboxylic acid) has been synthesized and characterized by single-crystal X-ray diffraction studies and FT-IR. Structural determination reveals that there are two crystallographically independent strontium ions in 1. The coordination geometry of Sr(1) is a nine-coordinated distorted monocapped tetragonal antiprism, while Sr(2) is a nine-coordinated distorted monocapped tetragonal prism. The ligand pdc 2- takes two different connecting modes and links Sr(Ⅱ) centers to generate a 2D layer structure. The 2D layers are linked through O-H···O and O-H···N hydrogen bonds to form a 3D framework structure. Thermal stability and luminescent properties of complex 1 are investigated. 1 belongs to the monoclinic system, space group P21/n with a=10.7182(10), b=7.0377(6), c=29.225(3) , β=95.7170(10)o, Z=4, V=2193.5(3) 3 , M r=651.56, D c=1.973 g/cm 3 , F(000)=1296, μ=4.951 mm -1 , the final R=0.0318 and wR=0.0726 for 3938 observed reflections with I > 2σ(I).     

环境和生物样品中铂族金属的分析研究进展

评述了近年来环境和生物样品中痕量铂族金属的分析研究进展，重点介绍了样品的预处理和分离富集技术以及检测手段等。     

Poly(arylene ether)s,poly(arylene thioether)s,and poly(arylene sulfone)s derived from a dihydroxy(imidoarylene) monomer

Novel poly(arylene ether)s, poly(arylene thioether)s, and poly(arylene sulfone)s were synthesized from the dihydroxy(imidoarylene) monomer 1 . The syntheses of poly(arylene ether)s were carried out in DMAc in the presence of anhydrous K₂CO₃ by a nucleophilic substitution reaction between the bisphenol and activated difluoro compounds. Poly(arylene thioether)s were synthesized according to the recently discovered one-pot polymerization reaction between a bis(N,N′-dimethyl-S-carbamate) and activated difluoro compounds in the presence of a mixture of Cs₂CO₃ and CaCO₃. The bis(N,N′-dimethyl-S-carbamate) 3 was synthesized by the thermal rearrangement reaction of bis(N,N′-dimethylthiocarbamate) 2 , which was synthesized from 1 by a phase-transfer catalyzed reaction. The poly(arylene thioether)s were further oxidized to form poly(arylene sulfone)s, which would be very difficult, if not impossible, to synthesize by other methods. All of the polymers described have extremely high T_gs and thermal stability as determined from DSC and TGA analysis. Poly(arylene sulfone)s have the highest T_gs and they are in the range of 298–361°C. © 1998 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 36: 1201–1208, 1998