Artificial light harvesting gel based on saponification-triggered gelation of aggregation-induced emissive BODIHYs

The present work provides a detailed study on saponification-triggered gelation of ester-based BODIHYs ( B1 and B2 ) derived from ethyl 4-(2-(benzo[ d ]thiazol-2-yl(cyano)methylene)-hydrazinyl)-benzoate ( L1 ) and diethyl 5-(2-(benzo[ d ]thiazol-2-yl(cyano)methylene)hydrazinyl)-isophthalate ( L2 ). The ligands and BODIHYs display good emission in the solution and solid states. This study describes the gelation of BODIHYs for the first time, wherein stable gels GL 2 and GB 2 were prepared via saponification-triggered gelation of L2 and B2 , respectively. The gelation and optical properties of the ligands and BODIHYs were compared through single-crystal X-ray diffraction studies. This work further explores the prospect of artificial light harvesting (ALH) via fabrication of ALHSs in the solution { B1 /rhodamine B ( RhB ) and B2 / RhB } and gel states ( GB 2 / RhB ). It was observed that in the presence of RhB , the emission intensities of BODIHYs and the gel decreased but those of RhB increased. The significant overlapping between the absorption spectrum of RhB and emission spectra of aggregates/gel suggests the possibility of energy transfer via noncovalent interactions. In these systems, B1 , B2 and GB 2 served as donors, whereas RhB served as an acceptor. The present work provides a detailed study on saponification-triggered gelation of ester-based BODIHYs ( B1 and B2 ) and explores their application in artificial light harvesting in solution and gel phase.