Series of chiral interpenetrating 3d-4f heterometallic MOFs: Luminescent sensors and magnetic properties

Series of chiral 3d-4f heterometallic MOFs based on a multidentate terpyridyl carboxylic acid ligand have been synthesized under the solvothermal conditions, namely, [LnZnL(CO3)2(H2O)](n) (Ln = Eu (1), Gd (2), Dy (3), Ho (4), Er (5), Tm (6), Yb (7), Lu (8)) (HL = 4'-(4-carboxyphenyl)-2,2':6',2-terpyridine). Compounds 1-8 were structurally characterized by the elemental analyses, infrared spectra, and single crystal X-ray diffractions. Compounds 1-8 exhibit the chiral interpenetrating 3D frameworks. Interestingly, 1 can serve as the luminescent sensor to detect nitrobenzene molecules with high sensitivity. The investigations on CD spectra of single crystals clearly assigned the Cotton effect, indicating that there exist two chiral enantiomers of 1-8 in the course of crystallization. The magnetic properties of 2 and 7 were exploited, respectively.