Fluorescent Supramolecular Organic Frameworks Constructed by Amidinium‐Carboxylate Salt Bridges. Issue 60 (23rd September 2021)

• Record Type: Journal Article
• Authors: Jiang, Hongqin; Xie, Linhuang; Duan, Zhiming; Lin, Kunhua; He, Qing; Lynch, Vincent M.; Sessler, Jonathan L.; Wang, Hongyu
• Is Part Of: Chemistry. Volume 27:Issue 60(2021)
• Page Start: 15006
• Page End: 15012
• Publication Date: 2021-09-23
• Subjects: aggregation-induced emission -- amidinium-carboxylate salt bridges -- fluorescence -- self-assembly -- supramolecular organic frameworks; Chemistry -- Periodicals; 540
• DOI: 10.1002/chem.202102296
• Languages: English
• ISSNs: 0947-6539

Abstract

Abstract: We report here a set of fluorescent supramolecular organic frameworks (SOFs) that incorporate aggregation‐induced emission (AIE) units within their frameworks. The fluorescent SOFs of this study were constructed by linking the tetraphenylethylene (TPE)‐based tetra(amidinium) cation TPE 4+ and aromatic dicarboxylate anions through amidinium‐carboxylate salt bridges. The resulting self‐assembled structures are characterized by fluorescence quantum yields in the range of 4.6∼14 %. This emissive behavior is ascribed to a combination of electrostatic interactions and hydrogen bonds that operate in concert to impede motions that would otherwise lead to excited state energy dissipation. Single‐crystal X‐ray diffraction analyses revealed that the length of the dicarboxylate anion bridges has a considerable impact on the structural features of the resulting frameworks. Nevertheless, all SOFs prepared in the context of the present study were found to display emissive features characteristic of TPE‐based AIE luminogens with only a modest dependence on the structural specifics being seen. The SOFs reported here could be reversibly "broken up" and "reformed" in response to acid/base stimuli. This reversible structural behavior is consistent with their SOF nature. Abstract : Fluorescent supramolecular organic frameworks were constructed by linking the tetraphenylethylene‐based tetra(amidinium) cation, TPE 4+, and aromatic dicarboxylate anions through amidinium‐carboxylate salt bridges. These self‐assembled structures can be reversibly "broken up" and "reformed" in response to acid/base stimuli and are characterized by fluorescence quantum yields in the range of 4.6 %∼14 %. This emissive behavior is ascribed to a combination of electrostatic interactions and hydrogen bonds that operate in concert to impede motions that would otherwise lead to excited state energy dissipation.