Self-Assembled Fluorescent Pt(II) Metallacycles as Artificial Light-Harvesting Systems

K. Acharyya (1) , S. Bhattacharyya (2) , H. Sepehrpour (1) , Shubhadip Chakraborty (3) , S. Lu (4) , B. Shi (1) , Xiaojian Li (5) , P.S. Mukherjee (2) , P.J. Stang (1)

1 University of Utah
2 IISc - Indian Institute of Science
3 IPR - Institut de Physique de Rennes
4 Zhengzhou University
5 USF - University of South Florida [Tampa]

Light-harvesting is one of the key steps in photosynthesis, but developing artificial light-harvesting systems (LHSs) with high energy transfer efficiencies has been a challenging task. Here we report fluorescent hexagonal Pt(II) metallacycles as a new platform to fabricate artificial LHSs. The metallacycles (4 and 5) are easily accessible by coordination-driven self-assembly of a triphenylamine-based ditopic ligand 1 with di-platinum acceptors 2 and 3, respectively. They possess good fluorescence properties both in solution and in the solid state. Notably, the metallacycles show aggregation-induced emission enhancement (AIEE) characteristics in a DMSO-H2O solvent system. In the presence of the fluorescent dye Eosin Y (ESY), the emission intensities of the metallacycles decrease but the emission intensity of ESY increases. The absorption spectrum of ESY and the emission spectra of the metallacycles show a considerable overlap, suggesting the possibility of energy transfer from the metallacycles to ESY, with an energy transfer efficiency as high as 65% in the 4a+ESY system. © 2019 American Chemical Society.

Domaines: Physique [physics]

K. Acharyya, S. Bhattacharyya, H. Sepehrpour, Shubhadip Chakraborty, S. Lu, et al.. Self-Assembled Fluorescent Pt(II) Metallacycles as Artificial Light-Harvesting Systems. Journal of the American Chemical Society, 2019, 141 (37), pp.14565-14569. ⟨10.1021/jacs.9b08403⟩. ⟨hal-02309942⟩