Novel Isopolyoxotungstate [H2W11O38]8- Based Metal Organic Framework: As Lewis Acid Catalyst for Cyanosilylation of Aromatic Aldehydes

A novel polyoxometalate-based metal organic framework (POMOF) constructed from isolated isopolyoxotungstate [H2W11O38](8-) cluster, {[Cu-2(bpy)-(H2O)(5.5)](2)[H2W11O38]center dot 3H(2)O center dot 0.5CH(3)CN} (1, where bpy = 4,4'-bpydine), has been synthesized under solvothermal conditions and charaterized by elemental analysis, infrared spectroscopy, and single-crystal X-ray diffraction. In 1, {W-11} clusters are alternately linked by two [Cu(2)(H2O)(1.5)(O-t)(3)(N)](2+) cations in an unexpected end-to-end fashion leading to a one-dimensional (1D) chain. Adjacent ID chains are linked through Cu(1)-bpy-Cu(2) in an opposite direction to form a two-dimensional (2D) wavelike sheet along the ab plane. These 2D sheets are further stacked in a parallel fashion giving rise to the 1D channels with copper(II) cations aligned in the channels. The resulting POMOF acted as a Lewis acid catalyst through a heterogeneous manner to prompt cyanosilylation with excellent efficiency.