1. Department of Chemistry, Bahauddin Zakariya University, Multan, Pakistan
2. Department of Chemistry, University of Arkansas at Little Rock, Little Rock, 72204, U.S.A.
3. Dipartimento di Chimica, Laboratorio di Chimica Bioinorganica, University of Florence, Via della Lastruccia, Rm. 188, Polo Scientifico, 50019, Sesto Fiorentino, Firenze, Italy