Angulo G, Organero J A, Carranza M A, Douhal A
Departamento de Química Física, Sección de Químicas, Facultad de Ciencias del Medio Ambiente, Universidad de Castilla-La Mancha, Avenida Carlos III, S.N., 45071 Toledo, Spain.
J Phys Chem B. 2006 Nov 30;110(47):24231-7. doi: 10.1021/jp064257g.
The picosecond dynamics of a bifunctional and H-bonding molecule, 7-hydroxyquinoline (7HQ), has been studied in a reverse micelle with increasing water content. The fluorescence kinetics has a complex behavior as the water content is changed. All reactions are irreversible, and a two-step mechanism is invoked to explain the observations. H2O/D2O exchange and excitation energy effects show that the second step has a higher barrier and that the corresponding reaction occurs through tunneling. The results clearly indicate two regimes of water nanopool behavior switching at W0 approximately 5 (W0 = [water]/[surfactant]). Water collective dynamics explains these observations. The lower fluidity of confined water within the reverse micelle with respect to normal bulk water alters the related H-bond network dynamics and therefore is responsible for the slower proton-transfer processes.
在水含量不断增加的反胶束体系中，对双功能氢键分子7-羟基喹啉（7HQ）的皮秒动力学进行了研究。随着水含量的变化，荧光动力学呈现出复杂的行为。所有反应均为不可逆反应，采用两步机制来解释这些观测结果。H₂O/D₂O交换和激发能效应表明，第二步具有更高的势垒，且相应反应通过隧穿发生。结果清楚地表明，在W₀约为5（W₀ = [水]/[表面活性剂]）时，水纳米池行为存在两种状态的转变。水的集体动力学解释了这些观测结果。相对于正常体相水，反胶束中受限水的较低流动性改变了相关的氢键网络动力学，因此导致了较慢的质子转移过程。
