(μ-Methylenediphosphonato-κ4 O,O′:O′′,O′′′)bis[(ethylenediamine-κ2 N,N′)palladium(II)] tetrahydrate

Abstract

The title compound, [Pd2(C2H8N2)2(CH2O6P2)]·4H2O, comprises of a binuclear molecule (point group symmetry 2), with a twofold rotation axis running through the central C atom of the methylenediphosphonate (MDP) anion. The PdII atom has a square-planar coordination environment defined by the N atoms of a bidentate ethylenediamine (en) ligand and two O atoms of the bridging MDP anion. In the crystal structure, metal complexes are arranged in layers parallel (001) and are sandwiched between layers containing disordered water molecules of crystallization. Extensive intralayer hydrogen bonds of the type N—H...O in the metal complex layer and O—H...O in the water layer, as well as O—H...O hydrogen bonds between the two types of layers, lead to the formation a three-dimensional network structure. The two lattice water molecules are each equally disordered over two positions.