The imino-carboxylate complexes [M(L)](-) (M = Mn, Ni) form the polymers {[
Mn( L)](2)Na4Cl2. 13H(2)O}(infinity) and {[Ni-( L)](2)Na-4(BF4)(2 infinity)
} in the presence of Na+; the degree of aggregation can be controlled by va
riation of the counteranion and the amount of Na+ present, the Na+ ions for
ming sandwiched layers between aggregates of [M( L)](-).