Abstract：
In the present paper, a simple method for analyzing the self-aggregation of dyes in a solution by a UV-visible absorption measurements is proposed. The concept of excess absorbance is introduced to determine an equation whose coefficients determine the parameters of the aggregation equilibrium. The computational peculiarities of the model are first discussed theoretically and then applied to sodium fluorescein in polar protic and aprotic solvents, as well as in aqueous solutions of methylene blue, which is a cationic dye. Although the experimental responses are very different, the model appears to work equally well in both cases. The model reveals that the trimer is the most likely configuration in both solvents. Furthermore, aggregation is strongly favored for the protic solvent. Interestingly, the model establishes that in aqueous solutions of methylene blue, the tetramer is the predominant form, which has long been assumed and recently demonstrated with sophisticated computational techniques.
摘要：
在本论文中，提出了一种通过UV-可见光吸收测量来分析溶液中染料自聚集的简单方法。引入过量吸光度的概念来确定一个方程，该方程的系数决定了聚集平衡的参数。首先从理论上讨论了模型的计算特性，然后将其应用于极性质子和非质子溶剂中的荧光素钠，以及在亚甲蓝的水溶液中，这是一种阳离子染料。虽然实验的反应是非常不同的，在这两种情况下，该模型似乎同样有效。该模型揭示了三聚体是两种溶剂中最可能的构型。此外，聚集对于质子溶剂是强烈有利的。有趣的是,该模型建立了在亚甲基蓝的水溶液中，四聚体是主要形式，这早已被假定，最近用复杂的计算技术证明了这一点。
