Synthesis, structures and properties of alkaline earth metal benzene-1,4-dioxylacetates with three-dimensional hybrid networks

Three novel alkaline earth metal benzene-1,4-dioxylacetates M(L)H2O (M = Ca, Sr or Ba, L = benzene- 1,4-dioxylacetate) with three-dimensional (3D) hybrid frameworks were reported. Both Ca(L)H2O (1) and Sr(L)H2O (2) crystallize in the monoclinic space group P2(1)/c while Ba(L)H2O (3) in the monoclinic space group P2(1). As determined by X-ray single-crystal analysis, in these compounds each metal ion is coordinated by eight O atoms: four from different carboxylate groups, two from one carboxylate group, one from the ether oxygen and one from one water molecule. Each L2- ligand coordinates to five alkaline earth metal centers through one of its ether oxygen atoms and two carboxylate groups adopting novel mu(3)-eta(2):eta(2) -bridging and mu(2)-eta(1):eta(1)-bridging coordination modes to give rise to a 3D network. The luminescence analysis shows that complexes 1 and 2 exhibit fluorescence in the solid state at room temperature. (c) 2006 Elsevier B.V. All rights reserved.