1. Department of Chemistry, College of Science, University of Tikrit, Tikrit, Iraq
2. Department of Chemistry, College of Education, University of Tikrit, Tikrit, Iraq
3. Department of Chemistry, College of Science, University of Salahaddin, Irbil, Iraq
4. Department of Chemistry, University College London, 20 Gordon Street, London WC1H 0AJ, UK
5. Department of Chemistry, King's College London, Britannia House, 7 Trinity Street, London SE1 IDB, UK
6. Institute für Chemie, Martin-Luther-Universität, Halle-Wittenberg, Kurt-Mothes-Str. 2, D-06120 Halle, Germany