Aggregation process of riboflavin molecules in binary mixtures: water – dioxane, water – DMSO, and ethanol – isobutanol, were investigated using spectroscopic methods and quantum-chemical calculation. It was shown that at a constant concentration of riboflavin and different ratios of binary mixtures, a deformation of the electronic absorption spectra with a hypochromic effect is observed. The observed changes are caused by the formation of a hydrogen bond and dipole-dipole interaction between riboflavin molecules, which is accompanied by a shift and resonance splitting of excited electronic levels.

中文翻译：

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核黄素分子团聚体的电子性质和结构

使用光谱方法和量子化学计算研究了核黄素分子在二元混合物中的聚集过程：水–二恶烷，水– DMSO和乙醇–异丁醇。结果表明，在恒定浓度的核黄素和不同比例的二元混合物的情况下，观察到电子吸收光谱的变形，具有低色度效应。观察到的变化是由核黄素分子之间氢键的形成和偶极-偶极相互作用引起的，伴随着激发电子能级的移动和共振分裂。