A family of luminescent metal-organic frameworks: synthesis, structure, and sensing studies

Herein we report three novel luminescent metal-organic frameworks (MOFs) viz. [Co(bpeb)(hfipbb) 0.5 ] n ( LCo-1 ), [Zn(bpeb) 2 (hfipbb)] n ( L-Zn ) and [Co(bpeb) 2 (oba)] n ( LCo-2 ) (where bpeb, hfipbb and oba represent (1,4-bis[2-(4-pyridyl)ethynyl]benzene), 4,4′-(hexafluoroisopropylidene)bis(benzoic acid) and 4,4 1 -oxybis(benzoic acid) respectively), which were synthesized through the solvothermal method and characterized by SC-XRD. Compounds LCo-1 and L-Zn adopt two-dimensional layered structures while compound LCo-2 is a 3-dimensional framework. The observed dimensionality changes of LCo-1 and LCo-2 from 2D to 3D are due to the different bridging modes of carboxylic acid ligands. In LCo-1 and L-Zn , the hfipbb ligand coordinates to the metal center in a monodentate fashion {(κ 1 )-(κ 1 )-(κ 1 )-(κ 1 )-μ 4 }, and in LCo-2 , dba coordinates in a {(κ 1 )-(κ 1 )-μ 2 } manner. Photoluminescence studies reveal that all three compounds show interesting sensing behavior towards nitroaromatic compounds. Herein we report three novel luminescent metal-organic frameworks (MOFs) viz. [Co(bpeb)(hfipbb) 0.5 ] n ( LCo-1 ), [Zn(bpeb) 2 (hfipbb)] n ( L-Zn ) and [Co(bpeb) 2 (oba)] n ( LCo-2 ) which were synthesized through the solvothermal method and characterized by SC-XRD.