A new Dy(III) complex, [KDy(sbtc)(H2O)2]·2H2O (1) (KH3sbtc: 5-sulfo-1,2,4benzenetetricarboxylic acid potassium salt), has been synthesized by solvothermal reaction of Dy2O3and KH3sbtc, and characterized by single crystal X-ray diffraction studies, elemental analysis, and FTIR. Single crystal X-ray diffraction reveals that1has a 3-D architecture, and there is only one crystallographically independent Dy(III) and K(I) in1. The coordination geometry of Dy(III) is a distorted monocapped tetragonal antiprism and K(I) is also a distorted monocapped tetragonal antiprism. The whole sbtc4−is aμ8-bridge linking four different Dy(III) cations and four different K(I) cations, giving a 3-D network structure. Thermal stability and solid luminescence of1were also investigated. [ABSTRACT FROM AUTHOR]