| Institution: | 1. Department of Inorganic, Organic and Biochemistry, Faculty of Pharmacy, University of Castilla-La Mancha, José María Sánchez Ibañez s/n, 02071 Albacete, Spain
Regional Center for Biomedical Research (CRIB), University of Castilla-La Mancha, Almansa s/n, 02071 Albacete, Spain;2. Renewable Energy Research Institute, University of Castilla-La Mancha, Paseo de la Investigación 1, 02071 Albacete, Spain;3. Department of Physical and Analytical Chemistry, Faculty of Experimental Sciences, University of Jaén, Campus Las Lagunillas, 23071 Jaén, Spain;4. Department of Inorganic, Organic and Biochemistry, Faculty of Pharmacy, University of Castilla-La Mancha, José María Sánchez Ibañez s/n, 02071 Albacete, Spain;5. Department of Physical Chemistry, Faculty of Pharmacy, University of Castilla-La Mancha, José María Sánchez Ibañez s/n, 02071 Albacete, Spain |
| Abstract: | This work is focused on unraveling the mechanisms responsible for the aggregation-induced enhanced emission and solid-state luminescence enhancement effects observed in star-shaped molecules based on 1,3,5-tris(styryl)benzene and tri(styryl)-s-triazine cores. To achieve this, the photophysical properties of this set of molecules were analyzed in three states: free molecules, molecular aggregates in solution, and the solid state. Different spectroscopy and microscopy experiments and DFT calculations were conducted to scrutinize the causative mechanisms of the luminescence enhancement phenomenon observed in some experimental conditions. Enhanced luminescence emission was interpreted in the context of short- and long-range excitonic coupling mechanisms and the restriction of intramolecular vibrations. Additionally, we found that the formation of π-stacking aggregates could block E/Z photoisomerization through torsional motions between phenylene rings in the excited state, and hence, enhancing the luminescence of the system. |
