Three families of heterotrimetallic chains with different topologies, have been obtained by reacting Schiff-base bicompartmental [Cu^II(L¹)] complexes and lanthanide(iii) salts, with (NHBu₃)₃[M(CN)₈] (M = Mo^V, W^V).

The reaction of [Cu(valen)] with Tb(NO₃)₃ and (Bu₃NH)₃[W(CN)₈] affords two types of crystals: [{W(CN)₈}Cu(valen)Tb(OH₂)₅]·2H₂O (1, a discrete trinuclear complex) and [{W(CN)₈}Cu(valen)Tb(OH₂)₄]·CH₃CN·H₂O (2, an infinite zig-zag chain), both compounds showing slow relaxation of the magnetization (H₂valen is the Schiff base resulting from the reaction of o-vanillin with 1,2-ethanediamine).

Four 3d–4f–4(5)d heterotrimetallic complexes, [L ² CuLn(H ₂ O) ₅ ( μ -NC)M(CN) ₇ ], were obtained from the association of the binuclear 3d–4f complexes and {M ^V (CN) ₈ } ³⁻ metalloligands.