A New Eight-connected Three-dimensional Network Based on a Tetranuclear Zinc Cluster Building Block

One interesting coordination polymer, [Zn2(1,2,4-BTC)(OH)(H2O)2]2·2H2O 1, has been synthesized from 1,2,4-BTC (1,2,4-BTC = 1,2,4-bentricarboxylate) under hydrothermal conditions and characterized by elemental analyses, IR, TG and single-crystal X-ray diffraction. Complex 1 crystallizes in triclinic, space group P1-, with a = 6.5200(13), b = 9.0600(18), c = 10.968(2) , a = 111.55(3), β = 92.07(3), γ = 95.03(3)o, C9H10O10Zn2, Mr = 408.91, V = 598.7(2) 3, Dc = 2.268 g·cm-3, F(000) = 408 and Z = 2. X-ray diffraction analysis reveals that complex 1 is a three- dimensional network built from tetranuclear Zn(II) building unit. In this complex, the Zn4 unit is an eight-connected knot, while 1,2,4-BTC a four-connected knot. This results in a CaF2 topology. To the best of our knowledge, such Zn4 unit is the first 8-connected building block built from asymmetry ligand.