Sensitive luminescent probes of aniline, benzaldehyde and Cr(VI) based on a zinc(II) metal-organic framework and its lanthanide(III) post-functionalizations

Abstract A novel zinc(II) metal-organic framework (MOF) {[(CH 3 ) 2 NH 2 ] 2 [Zn 5 (TDA) 4 (TZ) 4 ] . 4DMF} n ( 1 ) (H 2 TDA = thiophene-2,5-dicarboxylic acid and HTZ = 1 H -1,2,4-Triazole) based on Zn 5 (COO) 2 (TZ) 4 pentametallic clusters and thiophene-2,5-dicarboxylic acid was synthesized and structurally characterized via the mixed-ligand strategy. This MOF exhibits a uninodal 6-connected anionic framework with pcu topology and shows solvent stability. Post-functionalization via cation exchange of 1 with Eu 3+ and Tb 3+ afforded two lanthanide (III) functionalized MOFs: Eu 3+ @1 and Tb 3+ @1 . 1 as well as Eu 3+ @1 and Tb 3+ @1 were utilized as a highly selective and sensitive turn-off luminescent sensors for detecting aniline, benzaldehyde in DMF and Cr 2 O 7 2− , CrO 4 2− in water with low detection limits. More importantly, it is rather rare in MOF-based luminescent probes that 1 and its lanthanide (III) post-functionalized materials ( Eu 3+ @1 and Tb 3+ @1 ) can detect aniline, benzaldehyde, Cr 2 O 7 2− and CrO 4 2− . Furthermore, the sensitivity of 1 as luminescent probes for detecting aniline and benzaldehyde could be improved via post-functionalization with Eu 3+ ions.