Kinetic and Equilibrium Studies of Ion Association Reaction Between Ternary Heteropolyacids and Cat Ionic Dyes

1.金属离子如IV_A、V_A等与磷酸盐、砷酸盐、硅酸盐等杂多酸反应生成三元杂多酸。这种三元杂多酸可以与阳离子染料反应形成有色离子缔合物。有色离子缔合物可用于灵敏和选择性地测定磷酸盐、砷酸盐和硅酸盐：它们存在于水相中，漂浮在有机相和水相之间的界面上，并被萃取到有机相中。本研究对离子缔合反应的机理进行了探讨.本文用停流色谱法研究了三苯甲烷染料在水介质中的性质和两相平衡行为。三苯甲烷染料中心碳原子上的水分子加成是反应的速率控制步骤，中心碳原子上-OH的消除也是反应的速率控制步骤.各种f 关于我们 考察了影响杂多酸生成速率的因素：发现有机溶剂如醇和丙酮、季铵离子和质子化三苯甲烷染料都能加速杂多酸的生成反应.研究了杂多酸与阳离子染料的离子缔合反应。钼（VI）可以在水相中与孔雀石绿色（MG^+）形成缔合离子。钒钼酸盐与HMG^<2+>形成离子缔合物以形成黄色缔合物。磷钼钒酸、磷钼锆酸等三元杂多酸与阳离子染料形成离子缔合，磷钼酸、硼硅酸等三元杂多酸与阳离子染料形成离子缔合。这些离子缔合物可用于分光光度法测定磷酸盐、硅酸盐和钒酸盐.利用阳离子染料与磷、硅、钒形成离子缔合物，建立了灵敏、选择性好的测定方法。已通过分光光度法测定了亚ppt水平浓度的硅胶。少

1. Metal ions such as IV_A and V_A ions react with heteropolyacids of phosphate, arsenate and silicate to form ternary heteropolyacids. Such ternary heteropolyacids can react with cationic dyes to form colored ion associates. The colored ion associates can be used for the sensitive and selective determination of phosphate, arsenate and silicate : they are present in an aqueous phase, and floated on the interface between an organic and an aqueous phase and are extracted into an organic phase. In this research, the mechanism of the ion association reactions are investigated.2. The characteristics and behavior of triphenylmethane dyes in an aqueous medium and in two-phase equilibrium has been examined spectrophotometrically by a stopped-flow method. The addition of water molecule to the centered carbon atom of the triphenylmethane dyes was found to be a rate-determining step, and also the elimination of -OH from the centered carbon atom was found to be a rate-determining step.3. Various f … More actors affecting the formation rate of heteropolyacids was examined : organic solvent such as alcohols and acetone, quaternary ammonium ions and protonated triphenylmethane dyes was found to accelerate the formation reaction of heteropolyacids.4. Ion association reaction of heteropolyacids with cationic dyes was examined. Molybdenum (VI) can form an ion associate with malachite green (MG^+) in an aqueous phase. Molybdovanadete forms an ion associate with HMG^<2+> to form a yellow associate. The ternary heteropolyacids such as vanadomolybdophosphate and zirconomolybdophosphate form ion associate with cationic dyes, as well as molybdophosphate and molydbdosilicate do. These ion associates can be used for the spectrophotometric determination of phosphate, silicate and vanadate.5. The sensitive and selective methods for the determination of phosphorus, silicone and vanadium were developed on the basis of the formation of ion associate with cationic dyes. Silicone at concentrations of sub-ppt levels has been determined by spectrophotometry. Less