Department of Hydrosilicates, Institute of Inorganic Chemistry, Slovak Academy of Sciences, 845 36 Bratislava, Slovakia.
Phys Chem Chem Phys. 2021 Aug 28;23(32):17177-17185. doi: 10.1039/d1cp02762j. Epub 2021 Aug 4.
The non-covalent association is important for many fields of science, including processes in living systems. This work elucidates the mechanism of rhodamine 123 molecular aggregation in dispersions of a layered silicate and explains the mystery of the slow kinetics of this process. Chemometric analysis of thousands of spectra recorded by stopped-flow visible spectroscopy identified two parallel diffusion processes described by a two-phase exponential function. The slow and fast processes followed the super-Arrhenius kinetics and were assigned to lateral (surface) diffusion and inter-particle diffusion of dye cations, respectively. This work, supported by a large amount of data and their in-depth analysis, provides the first evidence of how these processes coexist together and provides quantitative analysis of their dependence on the reaction conditions. The implications of this work can be crucial for understanding the mechanism of the non-covalent association of adsorbed molecules in nature.
非共价相互作用在许多科学领域都很重要，包括生命系统中的过程。这项工作阐明了罗丹明 123 分子在层状硅酸盐分散体中聚集的机制，并解释了该过程动力学缓慢的奥秘。通过停流可见光谱记录的数千个光谱的化学计量分析，确定了两个平行的扩散过程，它们由两相指数函数描述。慢过程和快过程遵循超 Arrhenius 动力学，分别被分配给染料阳离子的横向（表面）扩散和颗粒间扩散。这项工作得到了大量数据及其深入分析的支持，首次提供了关于这些过程如何共存以及它们对反应条件的依赖性的定量分析的证据。这项工作的意义对于理解自然界中吸附分子的非共价相互作用的机制可能至关重要。
