The Fixed Propeller-Like Conformation of Tetraphenylethylene that Reveals Aggregation-Induced Emission Effect, Chiral Recognition, and Enhanced Chiroptical Property

Abstract

The propeller-like conformation of tetraphenylethylene (TPE) with aggregation-induced emission (AIE) effect was partially and completely fixed by intramolecular cyclization for the first time. The immobilization of propeller-like conformation was found to show great advantages in determining the enantiomer purity, identifying the chiral amines. The completely fixed conformers are resolved into M- and P-enantiomer, which showed mirror imaged CD and almost quantitative fluorescence quantum yield. Furthermore, it also showed a mirror and large circularly polarized luminescence dissymmetric factor, depending on the helicity of the enantiomer. The result provides the most direct and persuasive evidence for AIE via the restriction of intramolecular rotation and finds the new insight of the compounds in chiroptical property.

Synthesis, characterization, aggregation-induced emission, solvatochromism and mechanochromism of fluorinated benzothiadiazole bonded to tetraphenylethenes

“…[6][7][8] Recently, the aggregation induced emission (AIE) characteristics of small molecules and polymers has been proposed. [9][10][11][12] Tetraphenylethene (TPE) [13][14][15] with its propellershaped structure is one of the most studied examples for aggregation induced emission characteristics. Very recently, the TPE based molecules have been synthesized and investigated by Misra et al [16][17][18] The rational molecular design of the TPE based molecules makes it potential uses in non-doped OLEDs with a good color contrast.…”

Development of a Dual‐Fluorescence Emission Sensor Based on Photo‐Induced Electron Transfer and Aggregation‐Induced Emission Enhancement for Detection of Water

“…The DL values of RN‐1 are inferior to those (0.2 wt% for both THF and 1,4‐dioxane, and 0.04 wt% for and acetonitrile, respectively) of OM ‐ 1 , which may be attributed to the dynamic rotation of TPE unit, leading to the inhibition of the formation of PET inactive species RN‐1(H 2 O) (Scheme b). However, the obtained result by this work indicates that the main advantage of the dual‐fluorescence emission sensor RN‐1 based on PET and AIEE characteristics is to make it possible to detect water in low water content region and high water content region because the fluorescence emission by the suppression of PET occurs at the different wavelength with AIEE, compared to our previously reported PET sensors which are suitable for the detection of water in low water content region and simple AIEE‐type fluorescent sensors which are suitable for the detection of water in high water content region …”

“…On the other hand, an AIEE (aggregation‐induced emission enhancement) is photophysical property of organic fluorophores in the aggregation state, which is attributed to the emission enhancement induced by the aggregate formation upon addition of large amounts of water (over 40 wt% in almost every case) into the solution, leading to restricted intramolecular rotation (RIR) in the molecular structure. Thus, the aggregation can restrict the intramolecular free rotation, resulting in the elimination of radiationless (non‐emissive) relaxation of the photoexcited fluorophore . A typical AIEE dye is tetraphenylethene (TPE) and its derivatives which have created considerable interest in recent years for their facile synthesis, flexible structure modification, and prominent AIEE characteristic .…”

“…Thus, the aggregation can restrict the intramolecular free rotation, resulting in the elimination of radiationless (non‐emissive) relaxation of the photoexcited fluorophore . A typical AIEE dye is tetraphenylethene (TPE) and its derivatives which have created considerable interest in recent years for their facile synthesis, flexible structure modification, and prominent AIEE characteristic . Actually, the TPE‐based compounds in a dilute solution exhibit almost no emission due to radiationless relaxation of the excitons by dynamic rotation of the phenyl groups.…”

Tunable AICPL of (S)‐Binaphthyl‐Based Three‐Component Polymers via FRET Mechanism

“…These photosensitive polymers could exhibit the well‐resolved fluorescent patterns by photolithography of their emissive thin films . Recently, Zheng and co‐workers reported a series of achiral AIE‐active TPE‐based derivatives with the enhanced chiroptical property from the fixed propeller‐like conformation in the aggregate state, which could show obvious circular dichroism (CD) and strong circularly polarized luminescence (CPL) response behavior …”