Fluorescence enhancements of benzene-cored luminophors by restricted intramolecular rotations: AIE and AIEE effects

Abstract

Photoluminescence of simple arylbenzenes with ready synthetic accessibility is enhanced by two orders of magnitude through aggregate formation; viscosity and temperature effects indicate that the emission enhancement is due to the restriction of their intramolecular rotations in the solid state.

Silole‐Containing Polymers: Chemistry and Optoelectronic Properties

“…So far, polymers 106b and 106c are the rare cases in which a polymer can show the AIE property, already observed in many small molecules. [122,123] Polymer 106a was not AIE active, thus the long flexible spacer of the nonanyloxy group decoupled the silole pendants of 106b and 106c from the rigid polyacetylene backbone and enabled the silole groups to pack during aggregate formation. The mechanism for the AIE behavior was revealed by the observations of cooling-enhanced emissions of the polymer solutions, from which a model of restricted intramolecular rotations of the peripheral phenyls on the silole ring was proposed for the first time.…”

Conjugated Organosilicon Materials for Organic Electronics and Photonics

“…This phenomenon was explained by restricted intramolecular rotations of the phenyl rings in the nanoaggregates (with a large contribution to the nonradiative transition process found in solutions) [71] and observed for a series of similar phenylsiloles [72,73] as well as for other bulky molecules [74]. PSP5 and other 1,1-disubstituted siloles can be synthesized in a convenient one-pot reaction by lithiation of dithenylacetylene followed by treatment with corresponding dichlorosilane [75].…”

Aromatic Hyperbranched Polymers: Synthesis and Application

“…The metallophthalocyanine-containing hb-PIs also showed good solubility in polar aprotic solvents and CHCl 3 and their M n varied from 25,300 to 31,800 Da. The T g values of these polymers were in the range of [217][218][219][220][221][222][223][224][225] C and the T d,5% varied from 440 to 487 C. Banerjee et al [143] synthesized a triamine monomer B 3 (1-18, Scheme 9a) with the aim of preparing fluorinated hb-PIs by the A 2 + B 3 approach using commercially available dianhydrides as A 2 monomers. However, during solution imidization of the amide acids that formed by the reaction of the dianhydrides and B 3 monomer, an appreciable amount of gelation was observed for all the molar ratios, except when 6FDA was used as dianhydride for reaction molar ratio of 1:1 and the solution concentration was maintained at 2.7 wt%.…”

“…Phenyl and naphthyl groups could form conjugated structures with the hb-PPS backbones through sulfide bridges, whereas the benzyl group showed almost no effect on the fluorescence properties of hb-PPS. The naphthyl-cored hb-PPS showed drastic fluorescence enhancement of about 10-to 18-fold higher than the original hb-PPS, indicating that the core structures are conjugated with the hb backbones and might have important effects on the structural rigidity of the hb backbones [218]. The naphthyl core was more restricted in its intramolecular rotations in comparison to the phenyl core, which could easily rotate.…”