We investigated the hydration dynamics in the nanosized water pool of an Aerosol-OT (AOT) reverse micelle (RM) using a prototropic (proton-donating) fluorescent dye, N-methyl-7-hydroxyquinolinium (NM7HQ⁺), as the probe. NM7HQ⁺ is a photoacid, and the deprotonation of its excited-state cationic form (C*) gives rise to a neutral keto species (K*). In the present study, the residence sites of C* and K* in water pools of various sizes were determined by monitoring their time-resolved fluorescence anisotropy. Additionally, the evolutions of the C* and K* bands in the time-resolved fluorescence spectra were analyzed by fitting the spectra to the sum of two lognormal peak functions. The time-dependent spectral shifts of the species with different formal charges revealed the characteristic hydration behavior at the interface of the anionic AOT headgroups and the bound water region, as well as the rotational and translational diffusion of the probe within the RM.

我们研究了质子传递给质子的荧光染料N-甲基-7-羟基喹啉（NM7HQ ⁺）作为探针在气溶胶-OT（AOT）反胶束（RM）的纳米级水池中的水合动力学。NM7HQ ⁺是一种光酸，其激发态阳离子形式（C *）的去质子化反应生成中性的酮类（K *）。在本研究中，通过监测其时间分辨的荧光各向异性来确定C *和K *在各种大小的水池中的驻留位点。此外，通过将光谱拟合为两个对数正态峰函数的和，分析了时间分辨荧光光谱中C *和K *谱带的演化。具有不同形式电荷的物质的随时间变化的光谱位移揭示了阴离子AOT头基与结合水区域的界面处的特征水合作用，以及探针在RM中的旋转和平移扩散。