1. Department of Chemistry; Ningxia Medical University; Yinchuan 750004 China
2. Department of Chemistry and GEMS Center; University of Connecticut; Storrs CT 06269 USA
3. Department of Chemistry; Tanta University; Tanta 31527 Egypt
4. Institute of Materials Science; University of Connecticut; Storrs CT 06269 USA
5. Department of Surgery and Neag Cancer Center; University of Connecticut Health Center; Farmington CT 06232 USA
6. School of Chemistry; National University of Ireland at Galway; H91 Galway Ireland