Aggregation induced phosphorescence of metal complexes: From principles to applications

Alkali Blues: Blue‐Emissive Alkali Metal Pyrrolates

“…Hence, the quantum yield again rises up to more than Φ =90 % . Restriction of intramolecular motion by aggregation and in the solid state, leading to enhanced fluorescence quantum yields, is a very common strategy (aggregation induced emission, AIE) . Similarly, emission enabled by confinement through metal‐ion chelation has been increasingly reported and is called the chelation‐enhanced fluorescence effect (CHEF effect) .…”

A Twisted Bay‐Substituted Quaterrylene Phosphorescing in the NIR Spectral Region

“…X‐ray diffraction clearly showed that the steric hindrance between the TfO substituents at the central bay position of the quaterrylene board triggers a strong deformation of the central perylene planarity, twisting the naphthyl portions of each perylene units. Remarkably, this unique core‐twisted quaterrylene was found to emit in the NIR spectral region, with a phosporescence maximum centered at 1716 nm at 77 K. Considering that, up to now, the library of NIR‐emissive organic materials that emit beyond 750 nm is truly limited and it is mostly based on metal complexes and chalcogen‐containing hybrids, [ ][ ] this finding is very promising in the design of efficient organic NIR‐emitting materials. Moreover, third‐order NLO measurements on solutions and thin film containing the relevant dye showed considerably high NLO second hyperpolarizability values (15.7 ± 0.2 × 10 −31 esu) in comparison with those reported in the literature for parent π ‐extended PAHs.…”

Aggregation Induced Phosphorescence in the Main Group

“…[3] One explanation for the AIE phenomenon is that upon aggregation of the molecules, intramolecular rotations and vibrations are restricted which concomitantly reduce the rates of non-radiative decay. [10] Phosphorescent materials are coveted for OLED applications due to their potential to attain a theoretical maximum of 100 % electroluminescence effi-ciency [vs. 25 % from fluorescent materials] due to the ability to harness light emission from triplet excitons. [8] Accordingly there have been many excellent reviews on the topic of fluorescent AIEgens to which the reader is referred.…”