Affiliation:
1. Dipartimento di Scienze Chimiche, Biologiche, Farmaceutiche ed Ambientali Università di Messina e Centro Interuniversitario di Ricerca sulla Conversione Chimica dell'Energia Solare (SOLAR-CHEM, sede di Messina) Via F. Stagno d'Alcontres 31 Messina 98166 Italy
2. Dipartimento di Scienze Matematiche e Informatiche, Scienze Fisiche e Scienze della Terra Università di Messina Via F. Stagno d'Alcontres 31 Messina 98166 Italy
Abstract
AbstractWe report the absorption spectra and photophysical properties of homo and hetero‐aggregate assemblies of a strongly emissive N‐annulated perylene dye (P) and of a dyad made of P and a methyl viologen derivative (P‐MV), in ethanol‐water solutions. In homo‐aggregate assemblies of P, the π‐π* fluorescence of the isolated chromophore is replaced by excimer emission at lower energy, with a lifetime of 900 ps, due to excimer formation from the initially prepared excitons. In homo‐aggregate assemblies of P‐MV, photoinduced charge separation, with formation of P+‐MV− species, occurs in 3 ps with a charge recombination of 20 ps. In hetero‐aggregate P/P‐MV systems, the light energy absorbed by the P components delocalizes over various P subunits, and when a P‐MV unit is reached, charge separation occurs; however, excimer emission is present for P/P‐MV ratio larger than 3 : 1, indicating that delocalized excitons within the hetero‐aggregate systems extend over a limited number of P chromophores.
Subject
General Chemistry,Catalysis,Organic Chemistry