Novel hydrogen-bonded three-dimensional networks encapsulating one-dimensional covalent chains: [M(4,4 '-bipy)(H2O)4](4-abs)2 center dot nH(2)O (4,4 '-bipy=4,4 '-Bipyridine; 4-abs=4-aminobenzenesulfonate) (M=Co, n=1; M=Mn, n=2)

Two novel compounds, [Co(4,4'-bipy)(H2O)(4)](4-abS)(2).H2O (1) and [Mn(4,4'-bipy)(H2O)(4)](4-abs)(2).2H(2)O (2) (4,4'-bipy = 4,4'-bipyridine; 4-abs = 4-aminobenzenesulfonate), have been synthesized in aqueous solution and characterized by single-crystal X-ray diffraction, elemental analyses, UV-vis and IR spectra, and TG analysis. X-ray structural analysis revealed that 1 and 2 both possess unusual hydrogen-bonded three-dimensional (3-D) networks encapsulating one-dimensional (1-D) covalently bonded infinite [M(4,4'-bipy)(H2O)(4)](2+) (M = Co, Mn) chains. The 4-abs anions in 1 form 1-D zigzag chains through hydrogen bonds. These chains are further extended through crystallization water molecules into 3-D hydrogen-bonded networks with 1-D channels, in which the [Co(4,4'-bipy)(H2O)(4)](2+) linear covalently bonded chains are located. Crystal data for 1: C22H30CoN4O11S2, monoclinic P2(1), a = 11.380(2) Angstrom, b = 8.0274(16) Angstrom, c = 15.670(3) Angstrom, alpha = gamma = 90degrees, beta = 92.82(3)degrees, Z = 2. Compound 2 contains interesting two-dimensional (2-D) honeycomb-like networks formed by 4-abs anions and lattice water molecules via hydrogen bonding, which are extended through other crystallization water molecules into three dimensions with 1-D hexagonal channels. The [Mn(4,4'-bipy)(H2O)(4)](2+) linear covalent chains exist in these channels. Crystal data for 2: C22H32WN4O12S2, monoclinic P2(1)/c, a = 15.0833(14) Angstrom, b = 8.2887(4) Angstrom, c = 23.2228(15) Angstrom, alpha = gamma = 90degrees, beta = 95.186(3)degrees, Z = 4.

新型化合物[Ni(en)_3]_2[Ni(en)_2(H_2O)_2]·[As_6V_(15)O_(42)]·4H_2O晶体的水热合成与表征

多金属氧酸盐因其在医药临床、工业催化、功能材料等方面的广泛应用而引起人们的关注 [1～ 6 ] ,其中 ,有关钒化学的研究一直很活跃 ,钒具有与钼、钨明显不同的结构特性 ,钒可以采取 VO4 ,VO5和VO6 方式配位 ,同时 ,钒的价态可以是 + 3,+ 4和 + 5价 .由于钒可采取多种配位方式及多种价态 ,与钼酸盐和钨酸盐相比 ,钒酸盐更具有结构柔顺性 ,同时易形成低价或混合价态物种 .在以往的文献中 ,有关 P- V- O体系多金属氧酸盐的水热合成的研究已有大量的报道 [7] ,在常规溶液合成中 ,人们已对As- V- O体系进行了相对深入的研究 ,而有关水热合成的研究报道却很少 ,已见报道的砷钒化合物有K6 [As6 V15O4 2 ( H2 O) ]· 6H2 O[8,9] ,[As8V14 O4 2 ( H2 O) 1/2 ]4 - [10 ] ,[As8V14 O4 2 ( X) ]6 - [11] ( X=SO2 - 3,SO2 - 4,H2 O) .为了探究水热条件下 As- V- O体系的反应特性 ,我们开展了这方面的研究工作 ,并取得了突破性进展 .本文采用中温水热技术合成了含有机基团...

Single-crystal X-ray structure and properties of K-10[Ni-4(H2O)(2)(AsW9O34)(2)]center dot 4H(2)O

The rational synthesis and the structural and magnetic characterization of a nickel cluster are presented. The compound comprises a rhomblike Ni4O16 group encapsulated between two-heptadentate tungstoarsenate ligands [AsW9O34](9-). The crystal structure of K-10[Ni-4(H2O)(2)(AsW9O34)(2)](.)4H(2)O was solved in monoclinic, P2(1)/n symmetry, with a = 12.258(3) Angstrom, b = 21.232(4) Angstrom, c = 15.837(3) Angstrom, beta = 92.05(3)degrees, V = 4119.1(14) Angstrom(3), Z = 2, and R = 0.0862. The crystal structure of the Ni(II) derivative was compared with that of the Cu(II), Zn(II), Co(II) and Mn(II) derivatives. The Ni4O14(H2O)(2) unit in the compound shows no Jahn-Teller distortion. On the other hand, the Ni(II) derivative shows ferromagnetic exchange interactions within the Ni4O16 group (J = 7.8 cm(-1), J' = 13.7 cm(-1)) and an S = 4 ground state, the highest spin state reported in a heteropoly complex. Its redox electrochemistry has been studied in acid buffer solutions using cyclic voltammetry. It exhibited two steps of one-electron redox waves attributed to redox processes of the tungsten-oxo framework. The new catalyst showed an electrocatalytic effect on the reduction of NO2-.

人体血浆中15种超痕量稀土元素的电感耦合等离子体质谱法测定

本文用电感耦合等离子体质谱法测定了人体血浆中的稀土元素。在优化的条件下 ,以内标法测得的各种纯水溶液的检测限在 0 .7(Eu)～ 5 .4(Gd) ng·L- 1范围内。研究了 K,Na,Ca,Fe等基体元素对稀土测定的影响。以 In为内标元素补偿样品基体效应以及灵敏度飘移。比较了直接稀释、HNO3- H2 O2 消解及 HNO3-HCl O4消解 3种样品处理方法 ,用 1% HNO3直接稀释样品可满足轻稀土元素的定量分析要求 ,方法的定量测定下限≤ 1μg·L- 1。

EQCM characterization of self-assembled kinetics of 4-pyridyl hydroquinone at Pt surface and its ion transfer in electrochemical redox

The adsorbed kinetics, proton transportation in electrochemical redox process of 4-pyridyl hydroquinone (4PHQ) self-assembled monolayer (SAM) modified Pt electrode were studied by electrochemical quartz crystal microbalance (EQCM) in situ. It proved that the electrode was modified by a monolayer and underwent a rapid electron transfer. It was a slow adsorbed kinetic process. The ion transfer in the electrochemical redox at the SAM-modified electrode surface mainly involved into the hydrate hydrogen ion.

镍催聚1,4-聚丁二烯橡胶的e_y,[Z]和f值与其内在的相关性

比较稀土催聚1，4—聚丁二烯橡胶和几种不同温度下聚合的镍催聚1，4—聚丁二烯橡胶的σｙ 和［η］，从中得知链缠结的变化是影响σｙ 和［η］以及 τ的主要原因，而微观结构的变化可能是影响链缠结的因素之一，1，4—聚丁二烯橡胶的加工性能与链缠结有关。

Synthesis and structure of [NH4](4)H[(PMo8V4V2O42)-V-IV-O-V].24H(2)O

[NH4](4)H[(PMo8V4V2O42)-V-IV-O-V] . 24H(2)O has been hydrothermally synthesized from ammonium vanadate and sodium molybdate in aqueous solution by adding phosphorous acid, and its structure determined by single crystal X-ray analysis. The heteropoly molybdovanadophosphate anion is a bicapped 'pseudo-Keggin' polyanion, two vanadium atoms are distributed at two 'capping' metal atom positions and other four vanadium atoms randomly distributed at eight metal atom positions. (C) 1998 Elsevier Science Ltd. All rights reserved.

二(2,4,4-三甲基戊基)膦酸萃取Er(Ⅲ)的动力学

用新型恒界面池法首次研究了二（２，４，４－三甲基戊基）膦酸在盐酸介质中萃取Ｅｒ（Ⅲ）的动力学，测定了流体线性流速、有机相浓度、水相浓度和酸度、温度及界面面积等因素对萃取速率的影响，提出其速率方程，求出萃取反应的活化能，并对萃取反应机理进行了探讨.

Electrocatalytic oxidation and flow amperometric detection of hydrazine at an electropolymerized 4-vinylpyridine/palladium film electrode

A poly(4-vinyl)pyridine (PVP)/Pd film electrode was constructed for the electrocatalytic detection of hydrazine. The preparation of the PVP/GC electrode was performed by electropolymerization of the monomer 4-vinylpyridine onto the surface of a glassy carbon electrode. Subsequently, palladium is electrodeposited onto the polymer modified electrode surface. The ion-exchange function of PVP polymer is helpful to this process in view of the tetrachlorapalladate anion. Compared with the Pd/GC electrode, the modified electrode displays a better mechanical stability in a flowing stream. The PVP/Pd film electrode exhibits higher sensitivity when detecting hydrazine with a detection limit of 0.026 ng (S/N=3).

Synthesis and characterization of soluble polyimides from 1,1-bis(4-aminophenyl)cyclohexane derivatives

A series of novel aromatic diamines (1-3) containing kinked cyclohexylidene moieties was synthesized by a reaction of excess aniline and corresponding methyl-substituted cyclohexanone derivatives. The structures of (1-3) were identifield by H-1 NMR, C-13 NMR, and FT-IR. The polymers were synthesized from the obtained diamines and various aromatic dianhydrides by the conventional polycondensation reaction followed by chemical imidization as well as high-temperature one-step polymerization. The inherent viscosities and weight-average molecular weights of the resulting polyimides were in the ranges of 0.55-1.58 dL/g and (7.4-15.2) x 10(4) g/mol, respectively. The prepared polyimides showed excellent thermal stabilities and good solubility. All polymers were readily soluble in common organic solvents such as tetrahydrofuran, chloroform, tetrachloroethane, etc., and the glass transition temperatures were observed at 290-372 degrees C.

Gas permeability in polyimides from oxydianiline and isomeric thiaphthalic dianhydride or 1,4-bis(dicarboxyphenoxy) benzene dianhydride

The gas permeability and permselectivity properties were investigated of polyimides, prepared from 3,3',4,4'- and 2,2',3,3'-thiaphthalic dianhydride (p-TDPA and m-TDPA, respectively), or 1,4-bis(3,4-dicarboxyphenoxy)- and 1,4-bis(2,3-dicarboxyphenoxy) benzene dianhydride (p-HQDPA and m-HQDPA, respectively), and 4,4-oxydianiline. The polyimides prepared from meta-dianhydrides, which have lower chain-segment packing density, possess higher permeability and lower permselectivity than those prepared from para-dianhydrides. Copyright (C) 1996 Elsevier Science Ltd.

Synthesis and structure of 1:1 complex of ethylphenyltin dichloride with N-4-methoxyphenyl-2-hydroxynaphthylideneimine

A novel organotin complex, EtPhSnCl(2) . 2HOC(10)H(6)CH = NC6H1OCH3 was synthesized, and its crystal structure was determined by X-ray diffraction method. The crystal is triclinic, belonging to space group, with unit cell parameters a = 1.150 8(5) nm, b = 1. 153 1(5) gm, c = 1. 004 6 (3) nm, alpha = 94. 15 (3)degrees, beta = 115.47 (3)degrees, r = 85. 94 (4)degrees, V = 1199 7(1) nm(3), Z=2, D-c=1.68 g/cm(3), mu=13. 20 cm(-1), F(000)=618 for 4 131 reflections tions. R=0. 047, R(w)=0. 047. The ligand coordinates to tin atom via phenolic oxygen atom. The complex has a distored trigonal bipyramidal structure, the phenolic oxygen atom of the ligand and one of two chlorine atoms occupy the axial position. The distance between noncoodinated nitrogen atom with phenolic oxygen atom is 0. 257 4 nm, which indicates that the intramolecular hydrogen bond of Schiff base ligand is retained in the complex.

胶束液相色谱／安培电化学检测尿样中的扑热息痛及4－氨基苯酚

用胶束液相色谱／安培检测器检测尿样中的扑热息痛及其主要水解产物４－氨基苯酚。采用１４．５μｍ的碳纤维电极作为工作电极，以高于临界胶束浓度的阴离子表面活性剂十二烷基磺酸钠（ＳＤＳ）作为液相色谱的流动相，尿样直接进样分析，扑热息痛和４－氨基苯酚的检测限分别为０．１３ｎｍｏｌ／Ｌ及０．７３ｎｍｏｌ／Ｌ（Ｓ／Ｎ＝２）。

15个乙烯-乙烯基化合物共聚物的取代基参数

本文应用取代基参数(SCS)方法处了15个EV共聚物的~(12)C NMR谱.它们是:(1)乙烯-α-烯烃共聚物,即乙烯-丙烯共聚物.乙烯-丁烯-1共聚物,乙烯-4-甲基-1-戊烯共聚物,乙烯-己烯-1共聚物和乙烯-辛烯-1共聚物;(2)乙烯-含氧乙烯基共聚物,即乙烯-甲基丙烯酸N,N-二甲基胺乙酯共聚物,乙烯-丙烯酸甲酯共聚物.乙烯-丙烯酸共聚物,乙烯-乙酸乙烯酯,乙烯-乙烯醇,乙烯-氧化碳共聚物(ECO)(?)乙烯-卤代乙烯共聚物及其它EV共聚物,即乙烯-氯化乙烯共聚物(包含氯化聚乙烯),乙烯-溴化乙烯共聚物,乙烯-苯乙烯共聚物(包含氢化丁二烯-苯乙烯共聚物)和乙烯-丙烯腈共聚物、得到了15种取代基的SCS参数.