1. Department of Chemistry, Angadi Institute of Technology & Management, Savagaon Road, Belagavi 590 009, India, Tel. , Fax:
2. Department of Chemistry, KLS, Gogte Institute of Technology, Udyambag, Belagavi 590 008, India, Tel. , Fax: ; Tel. , Fax:
3. Faculty of Sciences, Department of Inorganic Chemistry, University of Extremadura, Avda de Elvas, s/n, Badajoz E-06071, Spain, Tel. ; Fax: