A New 3D Metal-organic Framework with Tetranuclear Cadmium(II) Clusters: Synthesis, Structure, and Luminescent Property

A unique metal-organic framework [Cd-2(L)(1.5)(mu(3)-OH)(H2O)(2)]center dot 2H(2)O (1, H2L = 2,5-dibenzoylterephthalic acid) has been synthesized under hydrothermal conditions, and characterized by single-crystal X-ray diffractions, elemental analyses, IR spectra and fluorescence spectrum. The compound is of triclinic system, space group P (1) over bar, C33H27CdO14, Mr = 870.33, a = 12.2939(17), b = 12.5135(9), c = 13.2046(10) angstrom, alpha = 115.3190(10), beta = 96.9140(10), gamma = 109.7950(10)degrees, V = 1641.6(3) angstrom(3), Z = 2, D-c = 1.761 g/cm(3), F(000) = 862, mu(MoK alpha) = 1.366 mm(-1), R-int = 0.0148, R = 0.0240 and wR = 0.0639 for 5995 observed reflections with I > 2 sigma(1). X-ray analysis shows that the title complex exhibits a 3D framework with (4(12).6(3)) topology, in which the tetra-nuclear [Cd-4(mu(3)-OH)(2)] clusters act as 6-connected nodes, and the L ligands can be simplified to be linear connectors. Moreover, the thermal stability and fluorescence have been studied in detail.