CRYSTAL-STRUCTURE OF DIMERIC OCTAAQUABIS(MU-2,6-DICHLOROBENZOATO O,O,O')TETRAKIS (2,6-DICHLOROBENZOATO O)DILANTHANIDE(III) DIHYDRATES

New lantbanide(III) complexes of formula [Ln(2)(C7H3O2Cl2)(6) . 8H(2)O ].2H(2)O, where Ln = Ce(III), Pr(III), Nd(III), Tb(III) and Dy(III) cr ystallize in the triclinic system, space group P (1) over bar. The str ucture of the isomorphous complexes has been determined using X-ray di ffraction methods. The two lanthanide(III) ions in the molecule are he ld together in a dimeric unit by two carboxylate groups of the organic ligands and each lanthanide(III) ion is further bonded to two 2,6-dic hlorobenzoate ligands and four water molecules. Two molecules of water are in the outer coordination sphere Ln--O-(carboxylate) distances ar e in the range 2.323(3)-2.986(5), Ln--O-(water) 2.328(5) to 2.539(2)an d Ln--Ln 4.420(1) to 4.625(1) Angstrom.