The {Cu2I2} cluster bearing metal organic frameworks: crystal structures and fluorescence detecting performances towards cysteine and explosive molecules

Abstract

Two {Cu₂I₂} cluster-bearing metal organic frameworks (MOFs) of {[Eu(CuI)₂(INA)₃DMF]·0.95DMF}_n (Eu-CuI-INA) and {K[(CH₃)₂NH₂]Sr₄(INA)₂(DMF)₂{(Cu₂I₂)₂(INA)₈}·2H₂O}_n (Sr-K-CuI-INA, HINA = isonicotinic acid, DMF = N,N-dimethyl formamide) were prepared and characterized in this work. Both materials feature a three-dimensional (3-D) structure, in which the {Cu₂I₂} clusters and Eu³⁺ (or Sr²⁺) metal ions are coordinated by INA⁻ ligands with pyridine and carboxylic groups, respectively. Impressively, Sr-K-CuI-INA exhibits sensitive fluorescence sensing behaviors towards cysteine and nitro-bearing molecules, demonstrating potential FL sensing applications for bio and explosive molecules. This work would provide a good reference for designing fluorescent MOF probes containing CuI molecules.