1. Department of Chemistry; Mirpur University of Science and Technology (MUST); Mirpur Azad Jammu and Kashmir 10250 Pakistan
2. Department of Chemistry; Quaid-i-Azam University; Islamabad 45320 Pakistan
3. Department of Pharmaceutical Sciences; COMSATS Institute of Information Technology; Abbottabad 22060 Pakistan
4. Institut for Anorganische und Analytische Chemie; Technische Universität Braunschweig; Hagenring 30 38106 Braunschweig Germany