Unique Chiral Interpenetrating d–f Heterometallic MOFs as Luminescent Sensors

One novel three-dimensional (3D) 3d–4f metal–organic framework (MOF), [TbZn­(L)­(CO₃)₂(H₂O)]_n (<b>1</b>) [HL = 4′-(4-carboxyphenyl)-2,2′:6′,2″-terpyridine], has been successfully synthesized and structurally characterized. Structural analysis shows that compound <b>1</b> features a unique chiral interpenetrating 3D framework for the first time. The resulting crystals of <b>1</b> are composed of enantiomers <b>1a</b> (<i>P</i>4₁) and <b>1b</b> (<i>P</i>4₃), as was clearly confirmed by the crystal structure and the corresponding circular dichroism (CD) analyses of eight randomly selected crystals. The investigations on CD spectra based on every single crystal clearly assigned the Cotton effect signals. The powder X-ray diffraction measurement of <b>1</b> after being immersed in common solvents reveals that <b>1</b> possess excellent solvent stability. Furthermore, luminescent studies imply that <b>1</b> displays highly selective luminescent sensing of aldehydes, such as formol, acetaldehyde, and propanal