The first example of tetranuclear lanthanide complexes with 2-sulfobenzoate and 1,10-phenanthroline

Four tetranuclear complexes {[Ln2(2-SB)3(phen)3(H2O)2] · nH2O}2 (Ln = Sm (1), n = 3; Ln = Eu (2), n = 2; Ln = Tb (3), n = 2; and Ln = Dy (4), n = 2.5; 2-SB = 2-sulfobenzoate, phen = 1,10-phenanthroline) were formed by 2-sulfobenzoate linker. It is first example of tetranuclear lanthanide complex of metal centers through carboxylate group linker.