1. Department of ChemistryUniversity of Zululand Private bag X1001 Kwa-Dlangezwa 3880 South Africa
2. Department of ChemistryPittsburg State University Pittsburg 66762 Kansas USA
3. School of Chemistry and PhysicsUniversity of KwaZulu-Natal Private Bag X54001, Westville Campus Durban 4000 South Africa