Quantum Dot Surface Mediated Unprecedented Reaction of Zn2+ and Copper Quinolate Complex
journal contributionposted on 10.09.2015, 00:00 by Shilaj Roy, Satyapriya Bhandari, Arun Chattopadhyay
We report the reaction between Zn2+ ions, being present on the surface of ZnS quantum dot (Qdot), and copper(II) bis(8-hydroxyquinoline) (copper quinolate; CuQ2) complex, leading to the formation of luminescent ZnQ2 on the surface. This is contrary to the reactivity of copper complex based on Irving–William series in the liquid medium and thus indicating catalytic role of the Qdot surface. The rate of the reaction was observed to be first order with respect to the concentrations of both the reactants, with activation energy measured to be 74.3 kJ mol–1. Further, the reaction of the Zn2+ ions on the Qdot was observed to be the fastest with HQ, slower with MnQ2, and the slowest with CuQ2, all leading to the formation of ZnQ2 on the surface of the Qdot. The enhanced stability of the product complex on the surface, in the presence of dangling sulfide ions, indicated a new type of chemical reaction deserving special attention.