1. a Department of Chemistry, Georgian Technical University, Tbilisi 0175, Georgia; Department of Chemistry, Clark Atlanta University, Atlanta GA 30314, USA
2. b Department of Chemistry, Georgian Technical University, Tbilisi 0175, Georgia
3. c Department of Chemistry, Georgian Technical University, Tbilisi 0175, Georgia
4. d Department of Chemistry, Clark Atlanta University, Atlanta GA 30314, USA
5. e Department of Chemistry, Clark Atlanta University, Atlanta GA 30314, USA