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