Construction of Zn( ii ) and Cd( ii ) metal–organic frameworks of diimidazole and dicarboxylate mixed ligands for the catalytic photodegradation of rhodamine B in water

• Published in: CrystEngComm 2015-01, Vol.17 (9), p.1935-1943
• Main Authors: Lü, Chun-Ning, Chen, Min-Min, Zhang, Wen-Hua, Li, Duan-Xiu, Dai, Ming, Lang, Jian-Ping
• Format: Article
• Language: English
• Subjects: Catalysis; Catalysts; Density; Ligands; Metal-organic frameworks; Photodegradation; Recycled; Rhodamine; Three dimensional; Two dimensional
• ISSN: 1466-8033; 1466-8033
• DOI: 10.1039/C4CE02074J

A set of four metal-organic frameworks, namely, [Zn(1,3-BDC)(bmimb)] sub()n(1), [Zn(1,4-BDC)(bmimb)] sub()n(2), [Cd(1,3-BDC)(bmimb)] sub()n(3), and [Cd(1,4-BDC)(bmimb)] sub()n(4), have been prepared under solvothermal conditions (1,3-BDC = 1,3-benzenedicarboxylate; 1,4-BDC = 1,4-benzenedicarboxylate; bmimb = 4,4'-bis(4-methyl-1-imidazolyl)biphenyl). The long bmimb ligand (N...N separation of ca.14.1 Aa) induces interpenetration of 1, 2 and 4 to increase both the framework stability and the density of effective catalytic metal centers. Compounds 1, 2 and 4 are interpenetrated 3D structures while 3 features a 2D structure. Compound 1 exhibits a parallel 2D arrow right 3D polycatenation while 2 and 4 are isomorphous and feature 3D arrow right 3D interpenetration. Compounds 1-4 fluoresce in the range of 350-372 nm in the solid state, whereas compounds 2 and 3 catalyze the almost complete photodegradation of rhodamine B (RhB) in water within ca.4 h and can be recycled at least five times without loss in their crystallinity.