The layered structure of poly[[hexaaqua(μ4-benzene-1,2,4,5-tetracarboxylato)dicopper(II)] tetrahydrate]
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 μ4-coordination mode. The coordination environment of each pentacoordinated CuIIcentre 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 CuIIatoms. The alternation of (btec)4−ligands and SBP CuIIcentres leads to the formation of a planar two-dimensional covalent network of parallelograms, parallel to theabplane. 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.