1. a Central Department of Chemistry, Tribhuvan University, Kathmandu, Nepal Postal Address: POB 24411, Kathmandu, Nepal
2. b Institute of Polymeric Materials, University of Erlangen-Nürnberg, Martenstraße 7, D-91058, Erlangen, Germany
3. c Institute of Physics, Martin Luther University Halle-Wittenberg, D-06099 Halle/Saale, Germany
4. d Institute of Polymeric Materials, University of Erlangen-Nürnberg, Martenstraße 7, D-91058, Erlangen, Germany
5. e Instituto de Estructura de la Materia, CSIC, Serrano 119, 28006 Madrid, Spain