The agglomeration of self-assembled fibers of π-conjugated molecules is crucial to the formation of low-molecular-weight supramolecular gels. However, identification of the in situ spectroscopic signatures of fiber agglomeration has remained a challenging endeavor. Here, we use a combination of chiroptical techniques, namely circular dichroism (CD), magnetic circular dichroism (MCD), and fluorescence-detected circular dichroism (FDCD), to investigate the agglomeration of self-assembled fibers of a chiral low-molecular-weight gelator, l-alanine-substituted perylene imide bis(n-butyl) ester (PIBE). Surprisingly, we find that agglomerated PIBE fibers exhibit an opposite CD signature in comparison to the isolated PIBE fibers. In contrast, the MCD and FDCD responses do not change during the agglomeration process, revealing that the local structure in the individual fibers is unperturbed. Using Brownian dynamics simulations, we conclude that the effective charge on the fibers dictates the agglomeration process and that the final geometry of the agglomerated fibers is marked by crossed nodes.

π-共轭分子的自组装纤维的团聚对于低分子量超分子凝胶的形成至关重要。然而，纤维团聚的原位光谱特征的鉴定仍是一项艰巨的努力。在这里，我们结合手性技术，即圆二色性（CD），磁圆二色​​性（MCD）和荧光检测圆二色性（FDCD），来研究手性低分子聚合物的自组装纤维的团聚重量的胶凝剂，1-丙氨酸取代的im酰亚胺双（正丁基））酯（PIBE）。令人惊讶地，我们发现与分离的PIBE纤维相比，附聚的PIBE纤维表现出相反的CD特征。相反，在团聚过程中，MCD和FDCD响应不会改变，这表明单个纤维中的局部结构不受干扰。使用布朗动力学模拟，我们得出结论，纤维上的有效电荷决定了附聚过程，并且附聚纤维的最终几何形状由交叉节点标记。