1. Department of Chemistry, University of Zululand, Private Bag X1001, KwaDlangezwa 3880, South Africa
2. Department of Chemistry, College of Natural and Mathematical Sciences, University of Dodoma, P. O. Box 338, Dodoma, Tanzania
3. Institute of Physical Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, 01-224 Warsaw, Poland
4. Department of Chemistry, Pittsburg State University, Pittsburg, KS, 66762, USA
5. Department of Chemistry, Rhodes University, PO Box 94, Makhanda, 6140, South Africa
6. Institute for Nanotechnology Innovation, Rhodes University, PO Box 94, Makhanda, 6140, South Africa