[1] Indian Inst Technol Hyderabad, Dept Chem, Sangareddy 502285, TS, India
[2] Vignans Fdn Sci Technol & Res Univ, Dept Sci & Humanities, Guntur 522213, AP, India
[3] Pondicherry Univ, Dept Phys, Pondicherry 605014, India
[4] Clemson Univ, Dept Phys & Astron, Clemson, SC 29634 USA