A tetraphenylethene-based chiral polymer: an AIE luminogen with high and tunable CPL dissymmetry factor

A tetraphenylethene (TPE)-based chiral polymer (TPETyr) was synthesized by the polymerization of 1,2-bis(4-ethynylphenyl)-1,2-diphenylethene (M-1) and 3′,5′-diiodo-N-α-tert-butoxycarbonyl-O-octyl-L-tyrosine methyl ester (M-2) via Sonogashira cross-coupling. Interestingly, the generated luminogen emits weak fluorescence in THF solution, but becomes strongly luminescent as nanoparticle suspensions upon addition of water, demonstrating a novel phenomenon of aggregation-induced emission (AIE). The resulting TPETyr can also exhibit a large CPL dissymmetry factor (glum) in both solution and aggregate states. More importantly, the glum can be tuned in the range of 0.44 to 0.08 by changing the content of water in THF solution.