The layered structure of poly[[hexaaqua( l4-benzene-1,2,4,5-tetracarboxylato) dicopper(II)] tetrahydrate]

Abstract

In the structure of the title compound, {[Cu2(C10H2O8)- (H2O)6] 4H2O}n, the benzene-1,2,4,5-tetracarboxylate ligand, (btec)4 , is located on a crystallographic inversion centre in a 4-coordination mode. The coordination environment of each pentacoordinated CuII centre is square pyramidal (SBP), formed by three water molecules and two carboxylate O atoms from two different (btec)4 ligands. The completely deprotonated (btec)4 ligand coordinates in a monodentate mode to four CuII atoms. The alternation of (btec)4 ligands and SBP CuII centres leads to the formation of a planar twodimensional covalent network of parallelograms, parallel to the ab plane. Hydrogen bonds between a basal water molecule and an apical one from an adjacent [Cu(btec)0.5(H2O)3] unit exist in the intralayer space. Hydrogen bonds are also present between the two-dimensional network and the water molecules filling the channels in the structure.