a
Department of Chemistry, Indian Institute of Technology Roorkee, Roorkee, India
E-mail: vinodfcy@gmail.com
;
Fax: 0091-1332-286202
;
Tel: 0091-1332-285801
b
King Fahd University of Petroleum and Minerals, Dhahran, Saudi Arabia
c
Chemistry Department, Jammia Millia Islamia, New Delhi