Sc2(pydc)2 unit based 1D, 2D and 3D metal-organic frameworks as heterogeneous Lewis acid catalysts for cyanosilylation

Three scandium metal-organic frameworks (Sc-MOFs), [Sc(pydc)(Hpydc)(H2O)]center dot H2O (1), [Sc-2(pydc)(3)(H2O)(4)]center dot 5H(2)O (2) and [Sc(pydc)(H2O)(NO3)] (3) with similar Sc-2(pydc)(2) building unit were prepared by using 2,3-pyridinedicarboxylic acid (H(2)pydc) ligand under hydrothermal conditions. Compound 1 exhibits a ladder-shaped chain with Sc-2(pydc)(2) units, which further construct a supramolecular characteristic with water molecules via hydrogen bond. Compound 2 features a waved layer made up of pydc(2)-ligands and two types of crystallographically different Sc(III) ions, among which Sc2 and pydc(2-) ligands constructed the Sc-2(pydc)(2) units. In compound 3, left and right helixes were alternately linked by the Sc-2(pydc)(2) units forming a hexagonal network with nbo-a topology. All the prepared compounds present effective heterogeneous Lewis acid catalytic functionality for the cyanosilylation of aldehyde.