Inorganic Crystal Engineering through Cation Metathesis: One-, Two-, and Three-Dimensional Cluster-Based Coordination Polymers
文摘
[Nb6Cl12(CN)6]4- and [Mn(L)]+ (L = salen-type ligand) have been used as complementary buildingunits to prepare cluster-based coordination polymers. Reactions between solutions of [Me4N]4[Nb6Cl12(CN)6] ([Me4N]+ = [(CH3)4N]+) and different [Mn(L)]+ complexes led to formation of three polymericmaterials 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 diffractionanalysis. The three compounds are built of [Nb6Cl12(CN)6]4- and [Mn(L)]+ (L = 5-MeO-salen; 7-Me-salen (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 three-dimensional 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 stackperfectly parallel to each other to form layers that are separated by ammonium cations. In 2, each clusteris coordinated by four [Mn(7-Me-salen)]+ complexes via CN- ligands and each Mn complex links twocluster units to give anionic layers parallel to the crystallographic ab-plane. The layers are stacked in astaggered 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(acacen)]+ complexesand each complex links two clusters to afford an anionic framework with cavities containing the ammoniumcations and solvent molecules. Temperature dependence of the magnetic susceptibilities indicate that thethree 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.