Syntheses, Structures and Luminescence Sensing Properties of Two Cd(II) MOFs Constructed from Mixed Ligands

Hydrothermally reaction of Cd(NO 3 ) 2 ·4H 2 O, pimelic acid (H 2 Pim) mixed with two N-containing ligands of 1,2-bis(2-methyl-imidazol-1-ylmethyl)benzene (1,2-mbix) or 1,3-bis(2-methyl-imidazol-1-ylmethyl)benzene (1,3-mbix) gave rise to two new Cd(II) MOFs, [Cd(Pim)(1,2-mbix)] ( 1 ) and [Cd(Pim)(1,3-mbix)]·H 2 O ( 2 ). Both MOFs were structurally characterized by IR and UV–Vis spectra, single-crystal and powder X-ray diffraction, thermogravimetric analyses. MOF 1 shows a fourfold interpenetrating dia network. Differently, MOF 2 shows a 2D → 3D interdigitated architecture base on the 6 3 hcb layer when 1,2-mbix was replaced by 1,3-mbix. The luminescent properties of 1 and 2 have been investigated. Furthermore, the luminescent quenching experiments suggest both MOFs exhibit good selectivity and sensitivity to detect Fe 3+ and Cr 2 O 7 2− in water.