A stable amine functionalized montmorillonite supported Cu, Ni catalyst showing synergistic and co-operative effectiveness towards C-S coupling reactions

Abstract

The objective of this work is to prepare a cheap and highly stable heterogeneous catalyst. This was done by a simple two step approach. The first step involved the preparation of an organic-inorganic hybrid material by covalent grafting of amines on K10 montmorillonite. In the second step the N atoms of the amine groups were co-ordinated to Cu and Ni ions. Both the covalent and co-ordination forces are strong enough to make the catalyst fairly stable during the catalytic runs. The amine functionalization was confirmed by Si-29 CP MAS NMR spectroscopy, FTIR spectroscopy and XPS analysis. The XPS analysis revealed Cu and Ni were present in their +2 oxidation states. This bimetallic system was discovered somewhat by curiosity when Ni was added to a previously well-established Cu catalyzed C-S coupling reaction in an attempt to enhance the catalytic activity. When this catalyst was employed in the C-S coupling reaction, it showed wonderful activity with 99% product yield, due to the synergistic effect of the metal duo.