Naphthalenyl-phenylacrylonitrile-based supramolecular aqueous artificial light-harvesting system for photochemical catalysis

Highly efficient aqueous artificial-light-harvesting systems (ALHSs) were successfully fabricated based on the supramolecular assembly of naphthalenyl-phenylacrylonitrile derivative (NPT), water-soluble pillar [5]arene (WP5), and three kinds of pigments (4,7-di(2-thienyl)-2,1,3-benzothiadiazole (DBT), Eosin Y (ESY), and sulforhodamine-101 (SR101)). The assembled ALHSs perform a high energy-transfer-efficiency (ΦETE) and antenna effect (90.9% and 40.6 for WP5⊃NPT-DBT, 81.5% and 39.1 for WP5⊃NPT-ESY as well as 71.3% and 38.4 for WP5⊃NPT-SR101), suggesting that the energy of WP5⊃NPT complex has been effectively transferred to pigment acceptors (DBT, ESY, and SR101). Notably, during the energy-transfer process of WP5⊃NPT-SR101 ALHS, a white light emission (ΦQY = 24.21%) could be achieved by tuning the molar-ratio of [NPT]/[SR101] to 250:1, which is close to that of natural light-harvesting system, displaying a promising application in simulating natural light-harvesting system. Furthermore, the WP5⊃NPT-SR101 ALHS was successfully utilized as nanoreactors to catalyze the free-radical dehalogenation reactions of 2-bromo-acetophenone, 2-bromo-4′-methylacetophenone, and 2-bromo-4′-nitroacetophenone with the yields of 92%, 90% as well as 95%, which realized the energy transformation from solar-energy to chemical-energy, displaying a potential prospect in the field of artificial photosynthesis systems.