12-Ring Network Coordination Polymer-- { [Cu(C4 N2 H10)4]2 • H4 V4 O14}n Formed by Linking cyclo-[H4 V4 O14]4- with Cu (C4 N2 H10)2+4 Cation Clusters1

A novel 12-ring network coordination polymer, { [Cu(C4 N2 H10)4]2 H4 V4 O14}n (denoted as QUST-4), was hydrothermally synthesized and structurally determined by X-ray single-crystal diffraction analysis. QUST-4 was crystallized in a monoclinic system with space group P21/n. The parameters of the unit cell are a = 1. 0497(2) nm, b = 1.6728(3) nm, c = 1.2857(3) nm, β = 94.14(3)°, V = 2. 2517(8) nm3, Z = 4, Dcal = 1.841 Mg/m3, R1 = 0. 1071, and wR3 = 0. 2703. The largest difference peak and hole were 2284 and -1040 e/nm3, respectively. The SBU(secondary building unit) of QUST-4 was a new cyclo- aggregate of polyoxovanadate cyclo-[H4V4O14]4-, different from cyclo-[V4 O12], which was condensed from two tetrahedral and two trigonal bipyramids via, alternate arrangement. Cu(piper)4(piper = piperazine) group connected the cyclo-[H4V4O14]4- anions to form the 12-ring network. The adjacent layers were linked by van der Walls forces.