Three new solvent-directed Cd(II)-based MOFs with unique luminescent properties and highly selective sensors for Cu(2+) cations and nitrobenzene.

Three new solvent-induced metal-organic frameworks (MOFs)-[Cd(H2L)(H2O)3]·NMP (), [Cd3(L)(H2O)4(OH)2] () and [Cd(L)0.5(H2O)]·H2O ()-were designed and successfully prepared via solvothermal reaction by multidentate phenyltetracarboxylic acid [1,1':4',1''-terphenyl]-2',3,3'',5'-tetracarboxylic acid (H4L) and Cd(ii) salts in various solvent systems. Structural analyses indicated that the H2L/L ligands took three different coordination fashions in , and thus resulted in diversity of the targeted MOFs. Solid-state luminescent properties of the three MOFs were studied under ultraviolet light irradiation at ambient temperature; in particular showed high selectivity and sensitivity for Cu(2+) ions and nitrobenzene because of the quenching effect, which thus could make it a potential crystalline material for detecting these substances. The mechanisms of the quenching effect and sensing properties of are discussed in detail.