Four new dinuclear uranyl complexes based on p- and m-toluic acid: Syntheses, structures, luminescent and photocatalytic properties

Four new uranyl complexes, [(UO2)(DMSO)(p-MBA)(2)](2) (1), [(UO2)(DMSO)(p-MBA)(2)](2) (2), [(UO2)(DMSO)(m-MBA)(2)](2) (3) and [(UO2)(Hm-MBA)(m-MBA)(2)](2) (4) (Hp-MBA = p-toluylic acid, Hm-MBA = m-toluylic acid, DMSO = Dimethyl sulfoxide), were synthesized. Structural analyses reveal that four complexes have similar structures of which two penta-coordinated ((UO2)(O-DMSO)(O-L)(2) in 1-3 and (UO2)(O-HL)(O-L)(2) in 4) uranyl units bridged by two benzoic acid ligands forming dinuclear units. Compounds 1 and 2 belong to two kinds of polymorph forms, C2/c and P (1) over bar space groups, respectively. The supramolecular structures of 1-4 are assembled into 3D network by hydrogen bond interactions and pi center dot center dot center dot pi stacking interactions. Furthermore, the photocatalysis properties of 1 and 2 for degradation of the rhodamine-B (RhB) upon 500 W xenon lamp irradiation have been examined. Elemental analysis, infrared spectroscopy, thermogravimetric analysis, DRS and luminescence properties were also discussed. (C) 2014 Elsevier B.V. All rights reserved.