12-ring network coordination polymer -: {[Cu(C4N2H10)4]2 • H4V4O14}n formed by linking cyclo-[H4V4O14]4- with Cu(C4N2H10)42+ cation clusters

A novel 12-ring network coordination polymer, {[Cu(C4N2H10)(4)](2) H4V4O14}(n) (denoted as QUST-4), was hydrothermally synthesized and structurally determined by X-ray single-crystal diffraction analysis. QUST4 was crystallized in a monoclinic system with space group P2(1)/n. The parameters of the unit cell are a = 1.0497 (2) nm, b = 3 3 1.6728(3) nm, c=1.2857(3) nm, 8=94.14(3)degrees, V=2.2517(8) mm(3), Z = 4, Dcal =1.841 Mg/m(3), R-1 = 3 0.1071, and wR(3) = 0.2703. The largest difference peak and hole were 2284 and -1040 e/nm(3), respectively. The SBU (secondary building unit) of QUST-4 was a new cyclo- aggregate of polyoxovanadate cyclo-[H4V4O14](4-), different from cyclo-[V4O12](4-), 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.