Zn2+-induced AIEE-Active Conjugated Oligomers for Highly Selective Recognition of Zn2+ with an Impressive Blue Shift

A novel conjugated oligomer (Co-imiPhenTPE) based on 4-(1H-imidazo[4,5-f][1,10]phenanthroline (imiPhen) and tetraphenylethene (TPE) moieties has been synthesized. The Co-imiPhenTPE showed Zn2+-induced aggregation induced emission enhancement (AIEE) with high selectivity. Moreover, the Zn2+-Co-imiPhenTPE complex exhibited a significant blue shift from 502 nm to 393 nm (109 nm) in ethanol/water (v/v=1 : 1). The transmission electron microscopy (TEM) measurements indicated that the thin sheet porous Co-imiPhenTPE was evenly dispersed into approximate spherical nanoparticles after the addition of Zn2+. The approach may provide insights for designing large blue-shifted fluorescent sensors.