Enhanced photoluminescence and the self-assembled fibrillar nanostructure of 5-(cholesteryloxy)methyl-8-hydroxyquinoline lithium in a gel state

Abstract

Soluble 5-(cholesteryloxy)methyl-8-hydroxyquinoline lithium(I) (LiChQ) was synthesized through the modification of 8-hydroxyquinoline lithium (LiQ) with cholesterol, and showed about 3 times more enhanced luminescence than pristine LiQ. When increasing the concentration of LiChQ up to 1 wt% in non-protic solvents, nanoscale fibers of 30–100 nm diameter were formed through self-assembly in a super-gel state. There was a red shift in the absorption of the gel in comparison to the solution, which indicates that LiChQ tends to form a J-aggregate in the gel state. We also investigated the gelation process of LiChQ using the Lippert–Mataga equation. We suggest that LiChQ has potential applications in luminescent devices and/or as a template for nanostructured optoelectronic materials.