Fluorescence turn-on chemodosimetric sensing of cyanide by cyanovinylterpyridine modified phthalonitrile and subphthalocyanine.

Terpyridine-attached phthalonitrile (Pn-TP) linked by cyanovinyl bond has been synthesized and employed for the preparation of subphthalocyanine (SubPc-TP) bearing conjugated terpyridine moieties. Both Pn-TP and SubPc-TP exhibited highly selective fluorescence turn-on in the presence of cyanide anions (CN) based on chemodosimetric sensing mechanism. The conjugation of the Pn-TP molecule was interrupted by the addition of CN at the cyanovinyl bond, showing the ratiometric fluorescence turn-on behavior.