The nickel(II) complexes of L(1) = 3-methoxysalicylaldiminato and L(2) = 3-(2-methoxyethoxy)s alicylaldiminato react with barium ions to afford bimetallic complexes characterized by a Ba to Ni ratio of 1/2. A structural determination of the complex (L(2)(2)Ni)(2)Ba(ClO4)(2) . 2H(2)O (2) shows that it crystallizes in the orthorhombic space group Pbca (No. 61) with 8 formula units in the cell having the dimensions a = 14.780(1) Angstrom, b = 24.888(2) Angstrom, and c = 27.291(2) Angstrom. In the presence of barium ions, the precursor complexes L(2)(1)Ni and L(2)(2)Ni change their configurations from trans to cis so as to offer a polyoxygenated coordination site to a barium ion and assemble themselves around that ion to yield bimetallic species. Structural analogies with the polyether complexes of barium are discussed. Solution studies point to a great sensitivity of 2 to the nature of the solvent, contrary to (L(2)(1)Ni)(2)Ba(ClO4)(2) . 2H(2)O (1). Indeed, an important dissociation is induced by solvents which display good donor properties and which are able to stabilize the barium ions via solvation.