1. Inorganic Chemistry Department, University of Yaounde 1, Yaounde, Cameroon
2. Université de Lille, LASIRE CNRS UMR 8516, Villeneuve d’Ascq, Lille, France
3. Institut Chevreul CNRS FR2638, Université de Lille, Villeneuve d’Ascq, Lille, France
4. School of Chemistry, Faculty of Engineering and Physical Sciences, University of Southampton, Southampton, SO17 1BJ, UK