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Viscosity behaviour of several samples ofGraham's salt with varying molecular weight has been studied. Reduced viscosity (η sp /c) versus concentration curves were found to be characteristic of polyelectrolytes. They are dependent on the molecular weight and can be reduced to straight lines by plotting the reciprocal of the reduced viscosity against the square root of concentration. The intrinsic viscosities obtained by extrapolation were found to be proportional to the square of molecular weights. The value of reduced viscosity at any particular concentration in the concentration range between 0.25% and 4.0% was linearly related to the molecular weight. Reduced viscosities were found to decrease considerably on addition of electrolytes. Reduced viscosity versus added salt concentration curves were remarkably molecular weight dependent. The pH of the medium seemed to have no effect at all. Bivalent salts reduce the viscosity to a much greater extent than monovalent ones. By keeping the concentration of the added salt constant and varying that ofGraham's salt, curves showing hump which disappeared at higher concentration of the added salt, were obtained. In the action of electrolytes the more important factor is the valency of cation rather than the ionic strength of the medium. Most observations confirm the already well-establishedFolding-Chain Theory of polyelectrolytes developed byKatchalsky, Fuoss and others.  相似文献   

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用UV光谱和平衡透析数据证实Ni(Ⅱ)-HSA和Ni(Ⅱ)-BSA的1:1体系内均有2个强偶合的金属中心,它们的LMCT谱带显示一种新型的减色效应,这一效应符合生色基跃迁偶极矩间的偶极-偶极相互作用机理。  相似文献   

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对一系列手性Salen和Wu唑啉配体与中心金属(Cu(II)的配合物催化2-苯基环已酮的不对称Baeyer-Villiger反应进行了研究,设计和合成了新型手性配体III,IV,V,对配合物V-Cu(II)进行了单晶X射线衍射分析,并考察了助氧化剂,溶剂等对反应活性和选择性的影响。  相似文献   

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吴志斌  张祖训 《分析化学》1996,24(9):1011-1014
本文对铜(Ⅱ)-腺嘌呤配位吸附波的极谱行为进行了研究。结果表明,当腺嘌呤浓度大于铜的浓度时,极谱波呈现为两电子还原配位吸附不可逆波。测定了配合物的组成及条件生成常数,对电极反应机制也进行了探讨。  相似文献   

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Cu(II)NEAE和Cu(II)NACN的NIR FT—SERS光谱研究   总被引:1,自引:0,他引:1  
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1 INTRODUCTIONStudiesofthecoordinationchemistryofzinc(II)havearousedmoreandmoreinterestinlastdecadeinviewoftheirbiologicalmodelingapplica tions[1 ,2 ] andsolid statematerials[3 ,4] .WehavebeeninterestedinthestudyoftransitionmetalcomplexesofN oxopyridine 2 thiol(…  相似文献   

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