Theoretical analysis of aggregation in block-copolymer films: The optical signature
| Autor: | Angelita M. Machado, Liliana Yolanda Ancalla Dávila, Leni Akcelrud, Ronaldo Giro, Marilia J. Caldas |
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| Rok vydání: | 2009 |
| Předmět: |
Chemistry
Supramolecular chemistry Stacking Condensed Matter Physics Atomic and Molecular Physics and Optics Electron localization function Delocalized electron Absorption edge Computational chemistry Chemical physics ZINDO Physical and Theoretical Chemistry Absorption (electromagnetic radiation) Quantum |
| Zdroj: | International Journal of Quantum Chemistry. 110:885-892 |
| ISSN: | 0020-7608 |
| DOI: | 10.1002/qua.21979 |
| Popis: | We focus this work on the theoretical investigation of the block-copolymer poly[oxyoctyleneoxy-(2,6-dimethoxy-1,4phenylene-1,2-ethinylene-phenanthrene-2,4diyl) named as LaPPS19, recently proposed for optoelectronic applications. We used for that a variety of methods, from molecular mechanics to quantum semiempirical techniques (AM1, ZINDO/S-CIS). Our results show that as expected isolated LaPPS19 chains present relevant electron localization over the phenanthrene group. We found, however, that LaPPS19 could assemble in a π-stacked form, leading to impressive interchain interaction; the stacking induces electronic delocalization between neighbor chains and introduces new states below the phenanthrene-related absorption; these results allowed us to associate the red-shift of the absorption edge, seen in the experimental results, to spontaneous π-stack aggregation of the chains. © 2009 Wiley Periodicals, Inc. Int J Quantum Chem, 2010 |
| Databáze: | OpenAIRE |
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