1. Department of Chemistry, Quaid-I-Azam University, Islamabad 45320, Pakistan
2. Department of Chemistry, Government Graduate College Toba Tek Singh, Punjab 36050, Pakistan
3. School of Chemistry and Physics, University of KwaZulu-Natal, Durban 4001, South Africa
4. CIBER-BBN, Networking Centre on Bioengineering, Biomaterials and Nanomedicine, Department of Organic Chemistry, University of Barcelona, 08028 Barcelona, Spain