Bis(mu-2-sulfonatobenzoato)bis[(1,10-phenanthroline)lead(II)] dihydrate

In the title centrosymmetric dimer, [Pb2(sbc)2(phen)2].2H2O [sbc is the 2-sulfonatobenzoate dianion (C7H4O5S) and phen is 1,10-phenanthroline (C12H8N2)], each Pb(II) ion is six-coordinated by four O atoms, viz. carboxylate and sulfonate O atoms from two sbc anions, and two N atoms from a 1,10-phenanthroline ligand. One 1,10-phenanthroline ligand and the carboxylate group of one sbc ligand are chelated to each Pb(II) cation, and the sulfonate group of the other sbc unit is monodentate. One O atom of the chelated carboxylate group also bridges to the other Pb(II) cation, so that each pair of Pb(II) ions is bridged by two sbc anions and has the same coordination environment, forming a dinuclear ring. Each pair of Pb(II) ions is thus connected by two different kinds of bridges, namely a carboxylate short bridge and a carboxylate-sulfonate long bridge. There is also a special position of 1 site symmetry at the centre of the two Pb(II) cations.