Turn-on fluorescent organogel triggered by complexation with silver

ORGN 714

Jangwon Seo, Jong Won Chung, zapper96@snu.ac.kr, and Soo Young Park. School of Materials Science & Engineering, Seoul National University, San 56-1, Shilim-dong, Kwanak-gu, Seoul, 151-744, South Korea
Supramolecular electronics have attracted a significant attention in a broad range of applications since the self-assembly of π-conjugated organic materials can form well-defined and highly ordered nanostructures with the controlled charge/energy transfer property as well as unique fluorescence modulation. Previously, we reported a highly fluorescent organogel from trifluoromethyl-based cyanostilbene derivative (CN-TFMBE), which originated from supplementary intermolecular interaction induced by peripheral four CF3 units and strong π-π interaction by rigid aromatics. (JACS, 2004, 126, 10232) In this work, we report a novel class of CN-TFMBE analogues with pyridine moiety as good binding site for metal coordination. Its binding with silver triggered a prompt formation of gel from initial sol state, accompanied by a remarkably enhanced and red-shifted fluorescence. This is probably due to the cooperative molecular interaction of the two bound ligands to induce planar conformation and J-type aggregation. Consequently, turn-on fluorescent organogel assisted by self-assembly of silver-complex was demonstrated successfully.