An AIE-active tetraphenylethene functionalized silver-tetrazolate coordination polymer for selective fluorescence sensing of explosives

An aggregation-induced emission (AIE)-active and highly coordinated polytetrazole luminogen was designed and synthesized by combining four tetrazole units with tetraphenylethylene (TPE), i.e. tetrakis[4-(1H-tetrazol-5-yl)phenyl]ethylene (H(4)ttazpe) which is weakly emissive in dilute solution and becomes highly luminescent in the aggregated state. Coordination self-assembly of a TPE-based multidentate tetrazole ligand with silver(i) ions can afford a unique fluorescent coordination polymer with (3,6)-connected rtl topology of [Ag(H(3)ttazpe)] in the cluster representation, in which H(3)ttazpe(-) serves as the first tetrakistetrazole ligand with a tetra-coordinating bridging mode. We demonstrate, for the first time, the use of the luminescent metal-organic framework (LMOF) with TPE as the core surrounded by four peripheral tetrazole groups for fast and sensitive florescence-based nitro-explosive detection in aqueous media.