通过光学方法(UV/Vis,荧光,本文报道了CD和RLS光谱)。所研究的卟啉的特征是存在于葡萄糖的中观位置,类固醇和葡萄糖类固醇部分,赋予主要疏水性卟啉平台在水性介质中的两亲性和溶解度。大环的聚集是由本体溶剂组成的变化驱动的,形成具有超分子手性的架构,由卟啉外围位置的立体中心引导。最终聚集物种的聚集行为和手性特性在很大程度上取决于辅助基团的数量和立体生成性,这些辅助基团决定了卟啉发色团的相互空间排列及其在更大结构中的进一步组织,通常可通过不同的显微镜检测,如AFM和SEM。动力学研究是理解聚集机制的基础,通常发现这取决于底物浓度。此外,分子力学计算可以深入了解控制自组装过程的驱动力的本质。这些组合方法的关键使用可以揭示手性功能化大环的整体自组装过程,对发展手性卟啉基材料具有重要意义。
An overview of the solvent-driven aggregation of a series of chiral porphyrin derivatives studied by optical methods (UV/Vis, fluorescence, CD and RLS spectroscopies) is herein reported. The investigated porphyrins are characterized by the presence in the meso-positions of glycol-, steroidal- and glucosteroidal moieties, conferring amphiphilicity and solubility in aqueous media to the primarily hydrophobic porphyrin platform. Aggregation of the macrocycles is driven by a change in bulk solvent composition, forming architectures with supramolecular
chirality, steered by the stereogenic centers on the porphyrin peripheral positions. The aggregation behavior and chiroptical properties of the final aggregated species strongly depend on the number and stereogenicity of the ancillary groups that dictate the mutual spatial arrangement of the porphyrin chromophores and their further organization in larger structures, usually detectable by different microscopies, such as AFM and SEM. Kinetic studies are fundamental to understand the aggregation mechanism, which is frequently found to be dependent on the substrate concentration. Additionally, Molecular Mechanics calculations can give insights into the intimate nature of the driving forces governing the self-assembly process. The critical use of these combined methods can shed light on the overall self-assembly process of chirally-functionalized macrocycles, with important implications on the development of chiral porphyrin-based materials.