Synthesis of two Cd-MOFs based on flexible trinitrogen ligand for CrO42-detection in harsh alkaline solution

A two-dimensional luminescent metal-organic framework (LMOF), {[Cd(tptb)2(H2O)2]center dot 2NO3}n(1), and a 3-fold interpenetrating three-dimensional framework with a new topology of 3,5-c net, {[Cd(tptb) (H2DOBDC)(H2O)]center dot DMF}n (2, H2DOBDC2- = 2,5-dihydroxyterephthalate; DMF = dimethylformamide), were synthesized and characterized based on flexible trinitrogen ligands, tptb (1,3,5-tris(4-pyridylsulfanylmethyl)-2,4,6-trimethylbenzene). Interestingly, compound 2 can not only potentially be used as a multi-functional luminescent sensing material for Cr2O72-, CrO42- and Fe3+ ions via luminescence quenching in DMA, but also can be as a highly selective and sensitive sensor for CrO42- at pH 13.0. And the luminescent quenching mechanisms also were explored. Such a Cd-MOF with good pH stability, water stability, interference immunity and regeneration ability can act as an ultrasensitive fluorescent sensor in the field of detection.

Automated summary

A two-dimensional luminescent metal-organic framework and a three-dimensional framework were synthesized using a flexible trinitrogen ligand tptb, with one compound showing potential as a multi-functional luminescent sensing material for different ions. The compound exhibited good pH stability, water stability, interference immunity, and regeneration ability, making it a promising ultra-sensitive fluorescent sensor in detection applications.