Zn2+-selective fluorescent turn-on chemosensor based on terpyridine-substituted siloles

Two terpyridine-containing siloles (1 and 2) have been synthesized and their optical and metal sensing properties have been investigated in this work. 1 and 2 display a high selectivity for Zn2+ in comparison with alkali and alkaline earth metal ions (Na+, K+, Mg2+, Ca2+) and other transition metal ions (Ba2+, Zn2+, Fe2+, Pb2+, Ni2+, Co2+, Hg2+, Ag+) upon excitation at 380 nm in THF. As being chemosensor, 1 with two terpyridine groups at both ends shows better Zn2+ sensing properties than 2 containing only one terpyridine group at end due to the formation of a metal–organic coordination oligomer or polymer.

► Two terpyridine-containing siloles (1 and 2) have been synthesized.
► 1 and 2 display a high selectivity for Zn2+ among various metal ions upon excitation at 380 nm in THF.
► 1 with two terpyridine groups at both ends shows better Zn2+ sensing properties than 2 containing one terpyridine group.