锌的平面三配位[Bu_4N][Zn(SC_6H_2Pr_3~i-2,4,6)_3]·Pr~iOH配合物的合成与晶体结构

在许多重要的金属蛋白中,都存在ⅡB金属与半胱氨酸残基配位的活性中心M(Cys-S)_n.锌、镉、汞与含硫配体的配位化学作为M(Cys-S)_n中心的化学基础,三配位的[M(SR)_3]被认为是金属蛋白中ⅡB金属的一种配位形式.而近年来,Koch报道了平面三配位的锌、镉、汞的硫酚配合物[(n-Pr)_4N][Zn(SC_6HMe_4-2,3,5,6)_3]和[PPh_4][Cd(SC_6H_2Pr_3~i-2,3,6)_3]及[(n-Pr)_4N][Hg(SC_6H_2Pr_3~i-2,4,6)_3]的晶体结构.他们在实验中由于晶体迅速失去溶剂而未能测定以2,4,6-三异丙基硫酚为配体的锌配合物的晶体结构.最近我们合成了这个配合物,并测定了其晶体结构.     

配位聚合物{[CoL][FeⅡFeⅢ(ox)3·1.5H2O]}∞的合成、波谱表征和磁学性质

A new Schiff base complex， CoL(ClO₄)·3H₂O (1) {L represents condensed from equal molar ratio of sali-cylaldehyde and diethylenetriamine} was synthesized and characterized. Further， a new coordination polymer， {[CoL][Fe^ⅡFe^Ⅲ(ox)₃·1.5H₂O]}_∞ (2)， was synthesized and characterized， where ox^2-=oxalate. The results of the IR and M?ssbauer spectra of 2 revealed that the coordination polymer exists 2-D layer structure in the solid state， and anions layer was formed by [^ⅡFe^Ⅲ(ox)₃]^- unit. The magnetic properties of 2 have been measured and the results indicate that there is magnetic ordering in the low temperature， which may arise from intermolecular ferromagnetic interactions or spin canted effects.     

配位聚合物{[MnL][FeⅡFeⅢ(ox)3·1.5H2O]}∞的合成及其磁学性质

合成和表征了一种新的Schiff碱配合物MnL(ClO4)*3H2O(1)(其中L为n(水杨醛)∶n(二乙撑三胺)=1∶1缩合而成的Schiff碱).1与FeSO4*7H2O和K3[Fe(ox)3]*3H2O(ox=oxalate)进一步反应,生成了双金属层状配位聚合物{[MnL][FeⅡFeⅢ(ox)3]*1.5H2O}∞(2).IR和Mssbauer谱测定结果表明,2具有二维层状结构,其阴离子层由[FeⅡFeⅢ(ox)3]-单元构成.变温磁化率(5K～100K)测试结果表明,2中的自旋载体之间存在反铁磁交换作用.5K时的磁滞现象表明2在低温时可能存在铁磁有序,这可能是亚铁磁或自旋倾斜造成的.     

瑞香素稀土配合物的合成和性质

自六十年代以来陆续发现稀土化合物具有一系列特殊的药效作用 ,使稀土元素在药物上的应用展现出广阔前景。目前 ,已有不少稀土化合物应用于临床 ,如抗凝血药物 3 磺酸异烟酸钕、左旋糖酸镨、钕混合物 ;消炎药水杨酸钐等。合成具有生物活性配体的稀土配合物是寻找有效稀土药物的一条途径。瑞香素是一具有抗菌、抗炎、抗凝血等生物活性的香豆素类化合物 ,其分子结构为 :稀土与香豆素类的配合物的合成与性质研究己有不少报道[1,2 ] 。为了进一步研究这类配合物的性质和生物活性 ,我们合成了六种瑞香素稀土配合物。1　实验部分1 .1　仪器及试剂…     

Solvothermal Synthesis, Crystal Structure and Electrochemical Property of Complex [Co(p-MBA)2(2,2''-bipy)(H2O)]·(H2O)

One novel complex [Co(p-MBA)2(2,2'-bipy)(H2O)]·(H2O) has been synthesized by the reaction of p-methylbenzoic acid with 2,2'-bipyridine in the solvent mixture of water and methanol. It crystallizes in triclinic, space group P-1 with a=0.70479(14), b=1.1211(2), c=1.6718(3) nm, α=103.806(3), β=90.795(3), γ=104.207(3)°, V=1.2399(4) nm3, Mr=512.41, Dc=1.373 g/cm3, Z=2, F(000)=532, μ=0.733 mm-1, R=0.0432 and wR=0.0957. The crystal structural analysis shows that the cobalt atom is coordinated with three oxygen atoms from two p-methylbenzoic acids and one water molecule and two nitrogen atoms from one 2,2'-bipyridine,forming a distorted square-pyramidal coordination geometry. The cyclic voltammetry behavior of the complex is also reported.     

M~＋＋BrCN─→MCN~＋＋Br气相反应的从头算研究

Ｍ~＋＋ＢｒＣＮ─→ＭＣＮ~＋＋Ｂｒ气相反应的从头算研究朱荣顺，戴树珊（云南大学化学系，昆明，６５００９１）关键词气相反应，过渡金属阳离子，溴化氰，从头算，相对论赝势对过渡金属离子与一些小分子的气相反应已有大量的实验和理论研究［１～５］，ＭｉｃｈｅｌＳ...     

过渡金属催化的炔烃芳构化反应

综述了过渡金属催化的炔烃环三聚芳构化反应的历史沿革及最新研究进展，并 重点对含有不同电性取代基的炔烃环三聚反应、几种典型的催化体系和作用机理、 该领域的一些前沿热点作了评述．     

La2O3,Y2O3-Mo次级发射材料研究

采用粉末冶金方法制备了La2O3，Y2O3-Mo次级发射材料，测试了各种材料的次级发射系数。结果表明在钼中加入稀土氧化物可以具有很好的次级发射性能。经过激活处理后，材料的最大次级发射系数均高于2．0，达到了材料使用要求的发射水平。应用扫描电镜(SEM)和光电能谱仪(XPS)研究了稀土元素在烧结体断口和发射前后在试样表面的分布情况。分析结果表明稀土元素易于在晶界处偏聚，且发射后试样表面稀土元素的相对浓度明显高于发射前的浓度。     

About the calculation of exchange coupling constants in polynuclear transition metal complexes

The application of theoretical methods based on the density functional theory with hybrid functionals provides good estimates of the exchange coupling constants for polynuclear transition metal complexes. The accuracy is similar to that previously obtained for dinuclear compounds. We present test calculations on simple model systems based on H. He and CH(2). He units to compare with Hartree-Fock and multiconfigurational results. Calculations for complete, nonmodeled polynuclear transition metal complexes yield coupling constants in very good agreement with available experimental data.     

On-site preconcentration and trace metal ions determination in the Okavango Delta water system, Botswana

Microcolumns containing 8-hydroxyquinoline azo-immobilized on controlled pore glass were incorporated in a field sampler for on-site collection, isolation and preconcentration of trace metal ions in waters of the Okavango Delta, Botswana. Sequestered trace metal ions were recovered by elution with 0.5 ml of 1.5 M nitric acid, and determined by graphite furnace atomic absorption spectrometry (GFAAS). This sampling and enrichment method minimizes sample contamination, and collection of large volumes of water samples for transporting, over long distances, to analytical laboratories is avoided.Data reported comprise one of the initial surveys on trace metal ion concentrations in waters of the Okavango Delta, Botswana. In waters with more efficient mixing, dissolved metal ion concentrations found were generally low with slightly elevated levels of manganese (7-19 μg l⁻¹), zinc (2.7-4.8 μg l⁻¹), nickel (0.2-2.5 μg l⁻¹) and copper (0.3-2.1 μg l⁻¹). For each trace metal ion, concentration levels seem to reflect zones of varying water conveyance, and show no obvious temporal and spatial variations apart from a slight increment from the inlet in the upper Delta to the outlets in the lower Delta.