Phonon Bottleneck and Long-Lived Excited States in pi-Conjugated Pyrene Hoop
| Autor: | Sebastian Fernandez-Alberti, Ricardo Franklin-Mergarejo, Tammie Nelson, Sergei Tretiak |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2017 |
| Předmět: |
Phonon
PI-CONJUGATED PYRENE HOOP General Physics and Astronomy 02 engineering and technology NA-ESMD 010402 general chemistry 01 natural sciences purl.org/becyt/ford/1 [https] Delocalized electron chemistry.chemical_compound Molecular dynamics purl.org/becyt/ford/1.4 [https] Physical and Theoretical Chemistry PHONON BOTTLENECK AND LONG-LIVED EXCITED STATES Organic electronics Otras Ciencias Químicas Relaxation (NMR) Ciencias Químicas 021001 nanoscience & nanotechnology Internal conversion (chemistry) 0104 chemical sciences chemistry Chemical physics Excited state Pyrene Atomic physics 0210 nano-technology CIENCIAS NATURALES Y EXACTAS |
| Zdroj: | CONICET Digital (CONICET) Consejo Nacional de Investigaciones Científicas y Técnicas instacron:CONICET |
| Popis: | In the last decade, recent synthetic advances have launched carbon-based π-conjugated hoops to the forefront of theoretical and experimental nvestigation not only for their potential use as bottom-up templates for carbon nanotube (CNT) growth, but also for the interesting excitoniceffects arising from the cyclic geometry, unique pi-system orientation, and unusual electronic interactions and couplings. In particular, cyclic materials based on pyrene, a common component in organic electronics, are popular candidates for the future design of pi-conjugated nanorings foroptoelectronic applications. Understanding the photophysical response in cyclic oligopyrenes can be achieved using Non-Adiabatic Excited State molecular Dynamics (NA-ESMD). Through NA-ESMD modeling, we reveal details of the nonradiative relaxation processes in the circular pyrenetetramer [4]cyclo-2,7-pyrenylene ([4]CPY) where we find that the strong non-adiabatic coupling combined with the dense manifold of excited states creates an internal conversion mechanism dominated by ultrafast sequential quantum transitions. However, we observe two long-lived electronic excited states that introduce a phonon bottleneck in the electronic relaxation process. In fact, the timescale for the electronic relaxation is almost exclusively dominated by the lifetimes of the long-lived states. We find that the states associated with the phonon bottleneck are separatedfrom lower energy states by large energy gaps and are characterized by localization on a single pyrene unit resulting in a spatial mismatch with strongly delocalized neighboring states. Fil: Franklin Mergarejo, Ricardo. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Quilmes; Argentina Fil: Nelson, Tammie. Los Alamos National Laboratory; Estados Unidos Fil: Tretiak, Sergei. Los Alamos National Laboratory; Estados Unidos Fil: Fernández Alberti, Sebastián. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Quilmes; Argentina |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|