二茂铁亚胺环钯化合物－－一种新型芳基氯化汞偶联催化剂

发现在催化量二茂铁亚胺环钯化合物催化下，芳基氯化汞可在湿和条件下偶联 ，以中等或高的收率生成联芳烃。对于铑盐不能催化偶联的邻位取代苯基氯化汞和 α－基氯化汞，在此体系中亦可发生偶联。以HMPA为溶剂，在x = 0.025（摩尔分 数）化合物1或2催化下与2.0当量氯化锂存在时，得到最好的催化效果。     

稳定氮氧自由基TMPO和TMPRO的合成与应用

本文评述了近年来4-氧-2,2,6,6-四甲基哌啶-1-氧自由基(TMPO)和2,2,5,5-四甲基吡咯啉-1-氧自由基(TMPRO)及其衍生物在合成和应用方面的进展,着重讨论了这些氮氧自由基的合成方法和作为自旋标记试剂的应用。     

PEO/PVAc共混体系辐射交联反应中溶胶分数与辐照剂量间的关系

In this paper, the relationship between T_m and composition of PEO/PVAc blend were studied and the Flory-Huggins parameter of the blend system were calculated. The experimental results show that this blend system is compatible and have only one glass transition temperature (T_g), so we can extend the relationship between sol fraction (S) and radiation dose (R) of linear polymer to the PEO/PVAc system. The Bb value of PEO/PVAc system were calculated, which is in good agreement with the experimental value.     

Synthesis and Properties of Novel Hemicyanine Dye-β-Cyclodextrin

A series of novel hemicyanine dye-β-cyclodextrin compounds： mono-6-deoxy-β-cyclodextrin-6-[p-（p-substituted styryl）pyridium] p-totylfulfonates were synthesized by the condensation of mono-6-deoxy-β- cyclodextrin-6-（p-methyl pyridinium） p-toluenesulfonate with （un）substituted benzaldehydes. Their structures were established by 1^H NMR, IR, UV-Vis and elemental analysis. The absorption and fluorescence properties of the novel compounds were measured in solution and the photostability of a selected hemicyanine dye-β-cyclodextrin compound was also investigated.     

离子液体[BMim]BF4对SDS水溶液表面活性和聚集能力的促进

采用表面张力测定法和核磁共振谱等方法研究了阴离子表面活性剂十二烷基硫酸钠(SDS)在水溶性室温离子液体[BMim]BF4/水混合溶剂中的表面性质及聚集行为, 发现极少量[BMim]BF4的介入就可以显著降低SDS的临界胶束浓度, 提高体系的表面活性; 且[BMim]BF4在混合溶剂中所占的摩尔分数(x1)在一定范围内(0相似文献   

Theoretical Study on the Isomerization Mechanism of Enol Ester from 2-Acyl-1, 3-cyclohexanediones

The present paper employed density function theory to investigate two reaction pathways for isomerization of enol ester proposed by Yang(path a) and the present authors(path a), respectively. The base catalytic effects of solvent triethylamine on these two reactions were also evaluated. It is demonstrated that path B is more preferable than path a due to low barrier height for the rate-determining step.     

Structure of Palladium( Ⅱ ) Complex with 2-Hydroxy-propane 1, 3-diamine-N,N,N'''' N'''',-tetraacetic Acid

The reaction of PdCl2 in water with 2-hydroxypropane-1, 3-diaminetetraacetic acid (HPDTA) gave the complex Pd (C11H16N2O9)·1. 5H2O, which was characterized by elemental analysis, IR, NMR and single-crystal X-ray diffraction. The spectroscopic and X-ray diffraction data show that Pd ( Ⅱ ) is coordinated by two nitrogen atoms and two car-boxylic oxygen atoms. The complex crystallizes in monoclinic space group Pc with a = 1. 1240(2), b=1. 1183(2), c=1. 2597(3) nm, β=96. 33(2)°V=1. 5737(6) nm3, Z = 4, R= 0.038. The structure contains two crystallographically independent molecules which have slightly different orientations and are connected by hydrogen bonds.     

物理老化对PEK-C、PES-C及其复合材料的玻璃化转变热焓松弛特征的影响

 本文用DSC技术研究了物理老化对PEK-C、PES-C及其共混物和复合材料玻璃化转变的影响.老化时间(t)延长,玻璃化转变温度(T_g)、热焓松弛峰温(T_max)、峰高(△C_pmax)和热焓(△H)提高;△H与lgt成线性关系.碳黑或碳纤维对PES-C的物理老化行为无影响,而反应性乙炔端基砜(ATS)固化物能限制PEK-C和PES-C在T_g以下温度的物理老化过程.利用物理老化能更为方便地判断多相体系的相容性,结果表明PEK-C/PSF为相容体系,而PEK-C/PES-C相容性较差.     

铂电极上异黄樟油和胡椒醛电氧化的SERS研究

采用循环伏安(CV)法和原位表面增强拉曼光谱(SERS)技术, 研究了非水体系中反应物异黄樟油和目标产物胡椒醛在粗糙铂电极上的电氧化行为, 发现胡椒醛在电位≥1.50 V时将进一步氧化, 而且从分子水平证实, 在胡椒醛的氧化电位(≥1.50 V) 下, 波长为632.8 nm的激光对胡椒醛的氧化有助催化作用. 由异黄樟油直接电氧化合成胡椒醛的电位(E)应控制在1.20 V相似文献   

Improvement on Simultaneous Determination of Cr(III) and Cr(VI) by Capillary Electrophoresis and Chemiluminescence Detection

Chromiumexistsindifferentoxidationstatesingroundwater,industrialwastewater,seawater,andsoilofourenvironment1,2.Chromium(III)isanessentialtraceelementforhumans,requiredforthemaintenanceofnormalglucose,cholesterol,andfattyacidmetabolism.Ontheotherhand,watersolublechromium(VI),intheformCr2O72-orCrO42-,ishighlyirritatingandtoxictohumansandanimals3.Itsacutetoxiceffectsincludeanimmediatecardiovascularshockandlatereffectsonkidney,liver,andblood-formingorgans.Therefore,itisnecessaryforriskassessme…