Achieving Purely‐Organic Room‐Temperature Aqueous Phosphorescence via a Two‐Component Macromolecular Self‐Assembly Strategy

Abstract

Manipulation of supramolecular behaviors and aggregation states represents an important topic in devising intriguing photofunctional systems. Here we report a twocomponent macromolecular self-assembly strategy for achieving aqueous room-temperature phosphorescence (RTP) in purely organic systems. Amphiphilic triblock copolymers are used to modulate the self-assembly of planar RTP molecules in aqueous solution, leading to the formation of sheet-like RTP objects with well-defined morphology, uniform crystalline nanostructures and excellent aqueous dispersity. In contrast, the addition of the planar RTP molecules into aqueous medium only leads to precipitation and quenching of RTP properties. Powder X-ray diffraction and single-crystal X-ray diffraction studies reveal that the amphiphilic triblock copolymers can assist supramolecular columnar packing of the planar RTP molecules where multiple non-covalent interactions stabilize the triplet excited states. Interestingly, it is found that luminescent signals of the sheet-like RTP objects can be extracted from strong fluorescent environments by phosphorescence mode and emission lifetime measurement.

Recent progress on pure organic room temperature phosphorescent polymers

“…Zhang et al. developed an innovative co‐assembly strategy for macromolecules [ 27 ] . The luminescent molecule 9‐acetyl‐3,6‐diiodocarbazole substituted with heavy atom iodine (RTP‐8) and block copolymers (PEO‐b‐PPO‐b‐PEO, PEO‐b‐PAA, PEO‐b‐P4VP) (Scheme 1) were co‐assembled into a sheet nanostructure with noncovalent bonds.…”

“…It should be noted that high-efficiency phosphorescence emission without being quenched by water could also be achieved through the doping process. Zhang et al developed an innovative co-assembly strategy for macromolecules [27] . The luminescent molecule 9-acetyl-3,6diiodocarbazole substituted with heavy atom iodine (RTP-8) and block copolymers (PEO-b-PPO-b-PEO, PEO-b-PAA, PEO-b-P4VP) (Scheme 1) were co-assembled into a sheet nanostructure with noncovalent bonds.…”

Room‐temperature phosphorescence from organic materials in aqueous media

“…In the same year, Zhang et al succeeded in constructing an organic RTP system in aqueous media based on a two-component macromolecular self-assembly strategy (Figure 21A). 64 The self-assembly of a planer RTP molecule, 9-Acetyl-3,6-diiodocarbazole ( 17) was modulated using an amphiphilic triblock copolymer (17-CA) that led to the formation of efficient RTP objects having sheet-like morphology with uniform nanostructures and excellent aqueous dispersity (Figure 21B). The triblock copolymer aided the columnar packing of the planer RTP molecules as shown by both single crystal and powder X-ray studies that ultimately stabilized the triplet state of the molecule by multiple supramolecular interactions (Figure 21C).…”

Aqueous solutions with information on solids: room-temperature phosphorescence of polysaccharide–benzophenone complexes

“…[1][2][3][4][5][6][7] Recently, the formation of complexes with macrocyclic host molecules, such as cyclodextrins and cucurbiturils, or amphiphilic block copolymers has enabled the observation of organic phosphorescence in aqueous solutions at room temperature. [8][9][10][11][12][13][14][15][16][17][18] These complexes in water are expected to be applied in bioimaging, exploiting their long emission lifetimes to avoid autouorescence from endogenous uorophores. 12,13 Consequently, long-lived RTP materials improve signal-to-noise ratios because of the elimination of background interference by time-resolved imaging techniques.…”