Supramolecular Aggregates of Tetraphenylethene-Cored AIEgen toward Mechanoluminescent and Electroluminescent Devices

Abstract

Luminescent materials possessing both the mechanoluminescence (MCL) and electroluminescence (EL) properties are the quest for sensing and optoelectronic applications. We report on the synthesis of a new tailor-made luminogen, 1,2-bis(4-(1-([1,1'-biphenyl]-4-yl)-2,2-diphenylvinyl)phenyl)-1,2-diphenylethene (TPE 5), using Suzuki coupling reaction with high yield. An aggregation-induced emission (AIE) active complex TPE 5 forms supramolecular spherical aggregates at the air-water interface of a Langmuir trough. As a consequence, a large enhancement of luminescence is obtained from the mono- and multilayer Langmuir-Blodgett films of TPE 5 owing to the AIE effect. The luminogen TPE 5 exhibits a reversible MCL response, displaying photoluminescence switching due to change in the crystalline states under external stimuli. The unique feature of luminescence enhancement upon aggregate formation is utilized for the fabrication of light-emitting diodes with low threshold voltage using supramolecular aggregates as the active layer. This work demonstrates an efficient strategy for obtaining controlled supramolecular aggregates of AIEgen with a potential in the dual applications of MCL and EL.

Finely Controlled Circularly Polarized Luminescence of a Mechano‐Responsive Supramolecular Polymer

“…[14,15] Mechano-responsive materials also usually exhibit emission properties under mechanical stress. [16][17][18] In most cases, this effect results from the formation of supramolecular nanostructures;m echanical stimulus triggers transitions between several crystalline and amorphous phases or between an aggregated and am onomeric state,w hich are responsible for changes in the luminescence emission. [19][20][21][22][23][24][25] Although mechano-responsive materials have been developed for mechanical stress sensing [20] and security tag applications, [21] owing to the limit of expression of both chirality and luminescence properties,m echano-responsive materials that enable control of CPL characteristics have been only two studies reported by Kawai [24] and Yamashita [25] groups.Inprevious studies,the researchers have reported the control of chirality in hydrogels composed of two components and al uminescence dissymmetry factor of two difluoroboron-b-diketonate complexes.I nc ontrast, the kinetically controlled mechano-responsive chiral supramolecular polymerization through the control of CPL property has not been reported, despite their benefits as the seed and building block in living supramolecular co-polymerizations.T herefore,t he investigation of CPL supramolecular polymerization generated by af inely tuned external stimulus (for example, rotation, pressure,a nd light) still remains as ignificant challenge.H erein, we report kinetic controlled CPL supramolecular polymerization with four l-o rd-a lanine branch side chains formed by the fine-tuning of am echanical stimulus.I nterestingly,C Da nd CPL signals were able to be finely tuned by controlling rotational speed;i ncreasing the rotational speed led to the acceleration of al arge enhancement of CD and CPL signals.…”

One‐step solvothermal synthesis of hollow Bi2WO6 photocatalyst

“…The results show that the band gap of Bi 2 WO 6 was narrowed by KCl and PVP modification, and the absorption edge was significantly red-shifted in the long wavelength direction, which increased the light absorption rate and further increased the photocatalytic activity. [32] Photocatalytic Performance Evaluation Photocatalytic degradation of RhB is an effective means to evaluate the photocatalytic performance of the catalyst. [33,34] The result of photocatalytic degradation of RhB under visible light is shown in Figure 9.…”

Designing highly fluorescent, arylated poly(phenylene vinylene)s of intrinsic microporosity

“…3 Typically, low molecular weight AIE chromophores possess a propeller-shaped structure with rotatable peripheral phenyl rings (rotors), 4 such as 1,1,2,3,4,5-hexaphenylsilole (HPS), 5 2,3,3-triphenylacrylonitrile (TPAN) 6 and 1,1,2,2,-tetraphenylethylene (TPE). 7 TPE derivatives have demonstrated a wide range of applications in optoelectronic devices, [8][9][10] bioimaging, 11 biosensors, 12 etc. due to their AIE properties.…”