1. College of Science, Engineering and Technology University of South Africa, Johannesburg 1710, South Africa
2. School of Chemistry and Physics, University of Kwazulu-Natal, Westville Campus, Private Bag X54001, Durban 4000, South Africa
3. Department of Chemical Sciences, Olabisi Onabanjo University, P.M.B. 2002, Ago-Iwoye 120107, Nigeria
4. Department of Chemistry, School of Physical and Chemical Sciences, Faculty of Natural and Agricultural Sciences, North-West University (Mafikeng Campus), Private Bag X2046, Mmabatho 2735, South Africa
5. Department of Chemistry, Faculty of Science, Obafemi Awolowo University, Ile-Ife 220005, Nigeria
6. Department of Chemical Sciences, University of Johannesburg, P.O. Box 17011, Doornfontein Campus, Johannesburg 2028, South Africa
7. Department of Biochemistry, Federal University of Technology, P.M.B 704, Akure 340110, Nigeria
8. School of Chemistry and Physics, University of Kwazulu-Natal, Pietermaritzburg Campus, Private Bag X01, Scottsville 3209, South Africa