Catalytic properties of a series of coordination networks: cyanosilylation of aldehydes catalyzed by Zn(II)-4,4 '-bpy-carboxylato complexes

Three porous crystalline coordination polymers, i.e. the three-dimensional framework {[Zn-3(4,4'-bpy)(3.5)(mu-O2CH)(4)(H2O)(2)](ClO4)(2)(H2O)(2)}(n) (1), the one-dimensional three-leg ladder {[Zn-3(4,4'-bpy)(3)(mu-O2CCH3)(4)(H2O)(2)](PF6)(2)(H2O)(2)}(n) (2), and the two-dimensional layered network {[Zn-3(4,4'-bpy)(4)(mu-O2CCH2CH3)(4)](ClO4)(2)(4,4'-bpy)(2)(H2O)(4)}(n) (3), have been investigated. All networks exhibit voids that contain the counter-ions and guest molecules, namely water for compounds 1 and 2, and water/4,4'-bpy for compound 3. In addition, compounds 2 and 3 are further stabilized by hydrogen bonds and pi-pi stacking interactions to form intricate supramolecular frameworks. The removal and reintroduction of guest water molecules for compounds 2 and 3 have been explored for their dynamic structural transformation. Interestingly, all Zn(II) compounds are active heterogeneous catalysts for the high-yield cyanosilylation of acetaldehydes in dichloromethane.