Phosphorescence resonance energy transfer from purely organic supramolecular assembly

Abstract

Phosphorescence energy transfer systems have been applied in encryption, biomedical imaging and chemical sensing. These systems exhibit ultra-large Stokes shifts, high quantum yields and are colour-tuneable with long-wavelength afterglow fluorescence (particularly in the near-infrared) under ambient conditions. This review discusses triplet-to-singlet PRET or triplet-to-singlet-to-singlet cascaded PRET systems based on macrocyclic or assembly-confined purely organic phosphorescence introducing the critical toles of supramolecular noncovalent interactions in the process. These interactions promote intersystem crossing, restricting the motion of phosphors, minimizing non-radiative decay and organizing donor–acceptor pairs in close proximity. We discuss the applications of these systems and focus on the challenges ahead in facilitating their further development. The construction of macrocyclic or assembly-confined phosphorescence resonance energy transfer systems in the solid-state, aqueous solution and hydrogels is reviewed, and the applications of these systems are discussed.