Das Arindam, Islam Sk Imadul, Das Dipak Kumar, Mitra Rajib Kumar
Department of Chemical, Biological and Macromolecular Sciences, S. N. Bose National Centre for Basic Sciences, Block-JD, Sector-III, Salt Lake, Kolkata 700106, India.
ACS Omega. 2018 May 28;3(5):5715-5724. doi: 10.1021/acsomega.8b00800. eCollection 2018 May 31.
The excited-state proton transfer (ESPT) rate of photo-acids in a confined medium depends on several physical parameters of the immediate environment. We introduce a new parameter in the form of charge type at the interface of reverse micellar (RM) systems to modulate the ESPT rate. We investigate the ESPT reaction of d-luciferin in mixed RM systems composed of nonionic polyoxyethylene(5)nonylphenylether (Igepal CO-520) with cationic didodecyldimethylammonium bromide (DDAB) and anionic sodium bis(2-ethylhexyl)sulfosuccinate (AOT) in cyclohexane (Cy) at different mole fractions of Ig ( ) and fixed hydration. ESPT is feeble in AOT RM, whereas it is favorable in the other two RMs. Addition of Ig is observed to facilitate ESPT in AOT RM linearly, whereas in DDAB, it shows a synergistic effect. The various physical parameters of water in the mixed RM water pool have been investigated using dynamic light scattering, Fourier transform infrared, and time-resolved fluorescence spectroscopy measurements to underline the ESPT mechanism in these mixed RMs.
受限介质中光酸的激发态质子转移（ESPT）速率取决于紧邻环境的几个物理参数。我们以反胶束（RM）系统界面处电荷类型的形式引入一个新参数来调节ESPT速率。我们研究了在环己烷（Cy）中，由非离子型聚氧乙烯（5）壬基苯基醚（Igepal CO - 520）与阳离子型双十二烷基二甲基溴化铵（DDAB）和阴离子型双（2 - 乙基己基）磺基琥珀酸钠（AOT）组成的混合RM系统中，不同Igepal（ ）摩尔分数和固定水合作用下d - 荧光素的ESPT反应。ESPT在AOT反胶束中较弱，而在其他两种反胶束中则较为有利。观察到添加Igepal可使AOT反胶束中的ESPT线性增强，而在DDAB中则表现出协同效应。利用动态光散射、傅里叶变换红外光谱和时间分辨荧光光谱测量研究了混合RM水池中水的各种物理参数，以强调这些混合反胶束中的ESPT机制。
