四苯硼钾从水到水——二氧六环混合溶剂中的标准迁移自由能和介质效应

Standard Gibbs Energy of Transfer of Potassium Tetraphenylborate from Water to Dioxane Mixed Solvents and the Primary Medium Effect

在温度298.15K时,用光度法测定了四苯硼钾在水及不同比例的水-二氧六环(DEDO)混合溶剂中的溶解度,进而对四苯硼钾从H2O到H2O-DEDO混合溶剂中的标准迁移自由能和介质效应进行了研究。结果表明,随物质的质量分数x(DEDO)的增大,ΔG0t呈现复杂的变化,当x<0.2,-ΔG0t随x的增大而增加;当x>0.2,-ΔG0t随x的增大而减小,在x=0.2附近,-ΔG0t出现极大值。当x>0.8时,ΔG0t变为正值,且随x的增大而急剧增加。对出现这种变化规律的原因进行了分析讨论。

The solubilities of potassium tetraphenylborate (KBPh_4) in water and water-dioxane mixed solvents at 298.15?K have been determined by spectrophotomentry. The standard Gibbs energies of transfer (ΔG0璽) of KBPh_4 from H_2O to H_2O-DEDO mixtures and the primary medium effect of KBPh_4 at 298.15?K were studied. The results show that ΔG0_t exhibits a complicated variation pattern with the increase of the fraction of DEDO at 298.15?K.When x<0.2,-ΔG0_t increases with x,and the-ΔG0_t decreases with increasing x when x>0.2. The-ΔG0_t exhibits a maximum value near x=0.2.When x>0.8, the ΔG0_t becomes positive , and increases sharply with x.The main reason for this change was analyzed and discussed.