Alkoxo bridged heterobimetallic CoIIISnIV compounds with face shared coordination octahedra: Synthesis, crystal structure and cyanosilylation catalysis

Abstract

The self-assembly reaction of the Schiff base N,N’-ethylenebis(2-hydroxyacetophenoneimine) (H2L), CoCl2··6H2O and [SnPh2Cl2] led to the alkoxo-bridged heteroorganometallic CoIIISnIV complex [{SnPhCl2}(1κO2:2κO2N2-μ-L)(μ-OMe){CoPh}]·CH3OH·H2O (1) or [{SnPhCl2}(1κO2:2κO2N2-μ-L)(μ-OEt){CoPh}] (2) in MeOH or EtOH, respectively. The structures of these complexes are authenticated by single crystal X-ray diffraction analyses. They are derived from an intermetallic (Sn to Co) phenyl shift, leading to face-shared distorted octahedral coordination geometries. The complexes were tested as homogeneous catalysts for the solvent-free cyanosilylation reaction of benzaldehyde with trimethylsilyl cyanide (TMSCN) under low power microwave irradiation at 50°C. They exhibited a high catalytic activity, yielding (for catalyst 1) up to 93% of the cyano-derivative from benzaldehyde in 90 minutes.