Multifunctional asymmetric D-A-D’ compounds: Mechanochromic luminescence, thermally activated delayed fluorescence and aggregation enhanced emission

A multifunctional luminescent material based on quinoxaline and triphenylamine groups: polymorphism, mechanochromic luminescence, and applications in high-efficiency fluorescent OLEDs

“…Mechanochromic luminescence (MCL) is another method for obtaining adjustable color emission in response to external stimuli, such as grinding, heating, solvent fuming, and so on, and it has attracted considerable attention in the fields of sensors, memory chips, and security ink. 17–19 To obtain distinct multi-color-change (more than three colors) emitters, the integration of two different fluorophores into one molecule with a D–A–D′ or D–A–A′ structure is a feasible strategy, transforming different dominant chromophores. 20,21 Z. Chi and C. Yang found that a donor–acceptor structured molecule can exhibit multi-color switching depending on the configuration changes of flexible groups, such as phenoxazine and phenothiazine.…”

Theoretical studies on the excited-state properties of thermally activated delayed fluorescence molecules with aggregation induced emission

“…39,40 Thus, the HOMOs are mainly localized on the stronger electron-donating unit, which is consistent with the previous works of asymmetric D1-A-D2 type molecules. 41 As mentioned above, the intramolecular hydrogen bond can increase the planarity, this could further increase the overlap between the HOMO and the LUMO with increased photoluminescence quantum yield and energy gap (DE ST ) between S 1 and T 1 . 42,43 Based on the characteristics of studied D1-A-D2 type molecules, there is almost no distribution for the HOMO on D1.…”

Construction of Mechanofluorochromic and Aggregation‐Induced Emission Materials Based on 4‐Substituted Isoquinoline Derivatives

“…[16][17][18] Obviously, this kind of molecules can greatly promote the development of MFC materials. [19][20][21][22][23][24][25][26][27][28][29] However, in some cases, it was found that the change of morphology was sometimes not enough to lead to the generation of mechanofluorochromism, revealing the complexity of the formation mechanism. [30,31] Additionally, traditional fluorescence skeletons often contain planar π-conjugated aromatic rings and emit very weak or almost no solid-state fluorescence because of suffering from the effect of aggregation-induced quenching, [32] which greatly limits its development in MFC materials.…”

“…Tang and co‐workers discovered an interesting and very important aggregation‐induced emission (AIE) phenomenon of some organic molecules which often had twisted molecular conformations [16–18] . Obviously, this kind of molecules can greatly promote the development of MFC materials [19–29] . However, in some cases, it was found that the change of morphology was sometimes not enough to lead to the generation of mechanofluorochromism, revealing the complexity of the formation mechanism [30,31] .…”