1. Computational and Bio-Simulation Research Group, University of Calabar, P.M.B 1115, Calabar 540221, Nigeria
2. Department of Pure and Applied Chemistry, University of Calabar, P.M.B 1115, Calabar 540221, Nigeria
3. Research Centre for Synthesis and Catalysis, Department of Chemical Sciences, University of Johannesburg, Johannesburg 2006, South Africa