CRYSTAL-STRUCTURE OF A POLYMERIC COMPLEX OF LEAD(II) WITH 2,6-DIHYDROXYBENZOIC ACID

The complex Pb2(DHB)4 . 3H2O (DHB = 2,6-dihydroxybenzoate(- 1)) has been prepared and characterized using single-crystal X-ray diffraction. The compound consists of a polymeric network which accommodates two types of lead ions. The coordination polyhedron around the first of them can be described as a distorted pentagonal bipyramid, where four carboxylate and one phenolic oxygens are the basal coordinating atoms, while the water molecule and a second phenolic group are in the apical positions. The second lead atom is involved in a dimeric Pb-Pb unit (metal-metal distance: 4.23 angstrom) bridged by two water molecules lying at distances of 2.59 and 2.61 angstrom, respectively. The coordination at each atom of this dimeric entity is completed by a bidentate carboxylate, a monodentate carboxylate, a water molecule and two phenolic groups resulting in a heavily distorted square antiprismatic stereochemistry. The Cd(II) complex is likely to have the same structure as the lead complex.