Inorganic crystal engineering through cation metathesis: One-, two-, and three-dimensional cluster-based coordination polymers

[Nb₆Cl₁₂(CN)₆]₄ and [Mn(L)]+ (L = salen-type ligand) have been used as complementary building units to prepare cluster-based coordination polymers. Reactions between solutions of [Me ₄N]₄[Nb₆Cl₁₂-(CN)₆] ([Me₄N]₊ = [(CH₃)₄N]⁺) and different [Mn(L)]⁺ complexes led to formation of three polymeric materials with the general composition [Me₄N]_4-n{[Mn(L)] _n[Nb₆Cl₁₂(CN)₆]} (1, n= 1; 2,n = 2;3,n = 3). The crystal structures of the three materials were determined from single-crystal X-ray diffraction analysis. The three compounds are built of [Nb₆Cl₁₂(CN)₆]^4- and [Mn(L)] ⁺ (L = 5-MeO-salen; 7-Mesalen (salen -N,N′-ethylenebis- (salicylidene)iminate); or acacen = N,N′-ethylenebis(acetylacetone imine)) building units that link together through two, four, or six cyanide ligands to form one-, two-, and threedimensional frameworks, respectively. In 1, each cluster is trans-coordinated by two [Mn(5-MeO-salen)]⁺ complexes via CN~ ligands and each Mn complex links two clusters to give anionic chains that stack perfectly parallel to each other to form layers that are separated by ammonium cations. In 2, each cluster is coordinated by four [Mn(7-Me-salen)] ⁺ complexes via CN^- ligands and each Mn complex links two cluster units to give anionic layers parallel to the crystallographic ab-plane. The layers are stacked in a staggered fashion along the crystallographic c-axis and are separated by cations and solvent molecules. In the three-dimensional framework of 3, each cluster is coordinated by six [Mn(acaceri)]⁺ complexes and each complex links two clusters to afford an anionic framework with cavities containing the ammonium cations and solvent molecules. Temperature dependence of the magnetic susceptibilities indicate that the three compounds contain high-spin Mn(III) ions, and no long-range order was observed down to 2 K. Thermal behavior of 1-3 is presented.