Abstract
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 {(kappa(1))-(kappa(1))-(kappa(1))-(kappa(1))-mu(4)}, and in LCo-2, dba coordinates in a {(kappa(1))-(kappa(1))-mu(2)} manner. Photoluminescence studies reveal that all three compounds show interesting sensing behavior towards nitroaromatic compounds.