Voltammetry of Viologens Revealing Reduction of Hydrophobic Interaction in Frozen Aqueous Electrolyte Solutions
Voltammetry of Viologens Revealing Reduction of Hydrophobic Interaction in Frozen Aqueous Electrolyte Solutions
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紫罗碱伏安法揭示冷冻电解质水溶液中疏水相互作用的减少
DOI：
10.1002/celc.201600560
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发表时间：
2017
期刊：
影响因子：
4
通讯作者：
and Tetsuo Okada
中科院分区：
文献类型：
--
作者：
Hui Qu;Makoto Harada;and Tetsuo Okada
紫精、甲基紫精（MV ~（2+））和苄基紫精（BV ~（2+））在冷冻水溶液中的伏安法研究表明，冷冻抑制了它们之间的疏水相互作用。还原紫精物质（MV 0或BV+），其在水中具有固有的差溶解度，在循环伏安图中产生尖锐的吸附峰。冷冻使峰变宽，并且峰增宽随着冷冻溶液中液相体积的减小而增加。这表明表面波已转化为通常的扩散控制波。因此，被吸附物之间的相互作用通过冷冻而减弱。此外，冷冻降低了β-环糊精（β-CD）与MV 0的络合常数，但略微提高了与BV+的络合常数。这也被解释为冷冻浓缩溶液中疏水相互作用的抑制。
Voltammetry of viologens, methylviologen (MV2+) and benzylviologen (BV2+) in frozen aqueous solutions reveals that freezing suppresses the hydrophobic interactions. Reduced viologen species (MV0or BV+.), which have intrinsically poor solubility in water, give sharp adsorption peaks in cyclic voltammograms. Freezing makes the peaks broader and peak broadening increases with decreasing the liquid phase volume in a frozen solution. This obviously indicates that the surface wave is transferred into the usual diffusion controlled wave. Thus, the interaction between adsorbates is weakened by freezing. In addition, freezing reduces the complexation constant of β‐cyclodextrin (β‐CD) with MV0but slightly enhances that with BV+.. This is also interpreted as the suppression of the hydrophobic interactions in the frozen concentrated solution.