Numerous luminogenic molecules with twist/rotor structures have showed pronounced aggregation-induced emission (AIE) effect, while planar conjugated molecules usually exhibit aggregation-caused quenching (ACQ) characteristics. However, development of emissive organic molecules with planar conformations is beneficial to achieving nanomaterials with high photostability for biological applications. Herein, six analogous planar molecules that show completely contrast emission behavior. 1,2-Di(2-thienyl)-ethene, 1,2-di(2-selenophenyl)-ethene, and (E)-1,2-bis(thieno[3,2-b]thiophen-2-yl)ethene molecules show common ACQ effect, while the planar (E)-1,2-diethyoxy-1,2-di(thiophen-2-yl)ethene (TVT(OEt)), (E)-1,2-diethyoxy-1,2-di(selenophen-2-yl)ethene (SVS(OEt)), and (E)-1,2-diethyoxy-1,2-di(thieno[3,2-b]thiophen-2-yl)ethene (TTVTT(OEt)) molecules are highly emissive in the solid state, exhibiting interesting AIE behavior. The experimental and theoretical results demonstrate that the photoisomerization is responsible for the unusual AIE activity of TVT(OEt), SVS(OEt), and TTVTT(OEt). Furthermore, the AIE TTVTT(OEt)-based nanomaterials exhibit specific imaging of lipid droplets with excellent photostability. The ease with this strategy paves a novel way for creating emissive molecular materials with planar conformations for biological and other applications.

Lei Yang;Pan Ye;Wenqiang Li;Weijie Zhang;Qian Guan;Chen Ye;Tao Dong;Xiaoxi Wu;Weijun Zhao;Xinggui Gu;谦 彭;本忠 唐;Hui Huang

Advanced Optical Materials

2018-5-7

Research on materials with pure organic room temperature phosphorescence (RTP) and their application as organic single-molecule white light emitters is a hot area and relies on the design of highly efficient pure organic RTP luminogens. Herein, a facile strategy of heavy-atom-participated anion–π⁺ interactions is proposed to construct RTP-active organic salt compounds (1,2,3,4-tetraphenyloxazoliums with different counterions). Those compounds with heavy-atom counterions (bromide and iodide ions) exhibit outstanding RTP due to the external heavy atom effect via anion–π⁺ interactions, evidently supported by the single-crystal X-ray diffraction analysis and theoretical calculation. Their single-molecule white light emission is realized by tuning the degree of crystallization. Such white light emission also performs well in polymer matrices and their use in 3D printing is demonstrated by white light lampshades.

Jianguo Wang;Xinggui Gu;Huili Ma;谦 彭;小波 黄;Xiaoyan Zheng;Simon H.P. Sung;Guogang Shan;Jacky W.Y. Lam;志刚 帅;本忠 唐

Nature Communications

2018-12-1

Four tetraphenylethylene (TPE) derivatives 1-4 were synthesized to explore the influence of intermolecular interaction and molecular packing modes on their mechanochromism (MC) and mechanoluminescence (ML) performances. Compounds 1 and 2 modified with carboxyl groups had strong intermolecular interactions and were MC-active and ML-inactive, while compound 3 functionalized with a carboxyl ester had self-reversible MC and ML. Single crystal study of these molecules suggested that besides intermolecular interaction, molecular packing was also important for MC and ML properties. The carboxyl ester-modified 3c had weaker intermolecular interactions than 1c/2c, but it formed an intact three-dimensional hydrogen-bonded network and moderate packing density, which can efficiently block non-radiative relaxation and lead to ML. While 1c and 2c had strong molecular interactions, the molecular packing density in 1c was rather low due to its porous structure and 2c had a defective hydrogen-bonded network. These defective packings allowed non-radiative energy loss and inactivated the ML property of these two molecules.

Guangxi Huang;Yuqing Jiang;Jianguo Wang;Zhen Li;Bing Shi Li;本忠 唐

Journal of Materials Chemistry C

2019

Cell staining is a fascinating research area where monitoring and visualizing different cell organelles can be done using fluorescence techniques. However, the design and synthesis of organelle-targeting fluorophores is still a challenge for several specific organelles. Herein, a platform for synthesizing efficient red-emitting aggregation-induced emission luminogens (AIEgens) with donor–acceptor characteristics is reported. The core molecule can be easily functionalized in order to modulate organelle targeting. The three synthesized AIEgens exhibit quantum yields of up to 39.3% and two-photon absorption cross-section values of up to 162 GM. The two zwitterionic AIEgens, CDPP-3SO₃ and CDPP-4SO_3, with the sulfonate function group, are successfully utilized for specific one-photon and two-photon imaging of the endoplasmic reticulum (ER) in live human cells. Substituting the zwitterionic nature with a singly positive charge group, one-photon and two-photon imaging of CDPP-BzBr shows mitochondrial specificity, indicating the importance of the zwitterionic group for ER-targeting. Owing to the good in vitro photostability, cell viability, and high efficiency, these red dyes serve as a good potential candidate for specific organelle targeting, as well as illustrate how such a platform can easily aid in the study of structure–property relationships for designing such probes.

Parvej Alam;Wei He;Nelson L.C. Leung;Chao Ma;Ryan T.K. Kwok;Jacky W.Y. Lam;Herman H.Y. Sung;Ian D. Williams;Kam Sing Wong;本忠 唐

Advanced Functional Materials

2020-3-1

White-light emissive materials with stable photophysical properties are of great importance for their potential applications in information display, fluorescent sensors, and optical-recording systems. Herein, an amphiphilic tetraphenylpyrazine (TPP)-based cage compound (TPP-Cage) was facilely synthesized by reaction of propeller-like TPP with aggregation-induced emission characteristics and triglycol monomethyl ether-substituted triazine. By immobilizing the twisted conformation of TPP, TPP-Cage showed obvious helical chirality in the solution and aggregated state. TPP-Cage emits strong deep blue fluorescence in solution due to the restriction of intramolecular rotation of the TPP unit. Its amphiphilic nature enables it to serve as an excellent light-harvesting platform to encapsulate diketopyrrolopyrrole (DPP) with aggregation-caused quenching effect in its hydrophobic cavity in aqueous medium, forming the DPP@TPP-Cage complex. Such inclusion prevents π-π stacking of DPP enabling it to emit strong yellow-light emission in the aggregated state. Due to the complementary emission colors of TPP-Cage and DPP, DPP@TPP-Cage exhibited stable white-light emission in the aggregated state and poly(ethylene glycol) film. This work not only introduces a promising strategy for development of chiral compounds through immobilization of propeller-like achiral molecules but also provides a prospective pathway for white-light emission based on supramolecular assembly.

Hai Tao Feng;Xiaoyan Zheng;Xinggui Gu;Ming Chen;Jacky W.Y. Lam;Xuhui Huang;本忠 唐

Chemistry of Materials

2018-2-27

The anionic polytriazole PI with a weight-average molecular weight of 190 300 was facilely and directly prepared in an excellent yield of 98.1% in 6 h by the well-established Cu(i)-catalyzed click polymerization of 4,4′-diazido-2,2′-stilbenedisulfonic acid disodium salt hydrate (1) and AIE-active tetraphenylethene (TPE)-containing diyne (2) under mild reaction conditions. PI is soluble in high polar solvents, and thermally stable with 5% loss of its weight at temperatures higher than 290 °C. The photo-physical property investigation showed that PI possesses the unique feature of aggregation-enhanced emission (AEE). By taking this feature, PI could be used for the specific detection of aluminum ions with a threshold as low as 31 ppb, which could potentially be used for strict drinking water purity control of the aluminum ion content.

Wenhui Dong;Haiqiang Wu;Ming Chen;Yang Shi;Jingzhi Sun;Anjun Qin;本忠 唐

Polymer Chemistry

2016-10-7

Conjugation-induced rigidity in twisting molecules provides a new facile but effective avenue toward solution and solid dual-state efficient luminogens. While conjugation rigidifies the molecular conformations in solution, the twisting structure prevents or alleviates detrimental close molecular packing in the solid states, thus synergistically yielding high efficiencies in both solution and solid states.

Gan Chen;Wenbo Li;Tianru Zhou;谦 彭;Di Zhai;Hongxiang Li;Wang Zhang Yuan;永明 张;本忠 唐

Advanced Materials

2015-8-1

Tetraphenylethene (TPE)-substitued silanes [(Ph₄C=C) _mSi(Ph)_n, m = 3-1, n = 3-1] are designed and synthesized, and their optical, thermal, and electrochemical properties are studied. Whereas they are nonluminescent in solutions, they become highly emissive when aggregated in poor solvents (such as water) or fabricated into thin films, demonstrating a novel phenomenon of aggregation-induced emission (AIE). Their amorphous films exhibit high fluorescence quantum yields (54.6-63.7 %). They enjoy high thermal stability with 5 % weight loss occurring at 320-420 °C. Multilayer electroluminescence (EL) devices (ITO/NPB/emitter/TPBi/LiF/Al) utilizing the silanes as emitting layers are fabricated, which give deep blue EL with maximum luminance and external quantum efficiency of 5672 cd/m ², and 1.6 %, respectively.

Zujin Zhao;Shuming Chen;Jacky W.Y. Lam;Carrie Y.K. Chan;Cathy K.W. Jim;Zhiming Wang;Chunlei Wang;Ping Lu;Hoi Sing Kwok;於光 马;本忠 唐

Pure and Applied Chemistry

2010

A new bis(aroylacetylene) containing triazole and fluorene moieties is synthesized by click chemistry. Polycyclotrimerization of the monomer is catalyzed by piperidine in refluxed dioxane, furnishing a regioregular poly(aroylarylene) in a satisfactory yield. The hyperbranched structure of the polymer is characterized spectroscopically with satisfactory results. The polymer enjoys no metal detriment and is soluble in common organic solvents such as tetrahydrofuran (THF), chloroform, dichloromethane (DCM), and N,N-dimethylformamide (DMF).

An Jun Qin;K. W.Jim Cathy;W. Y.Lam Jacky;Jing Zhi Sun;本忠 唐

Chinese Journal of Polymer Science (English Edition)

2009-3

Click polymerizations with remarkable advantages have been nurtured into powerful polymerization techniques with widespread applications. In this overview, several types of click polymerizations and their applications are briefly summarized. Of these, azide-alkyne click polymerizations (AACPs) are the most widely used due to the easy availability of the monomers and the stability of the products. AACPs catalyzed by Cu(i) and Ru(ii) can offer 1,4- and 1,5-regioregular PTAs, respectively. Meanwhile, 1,4-regioregular PTAs can also be obtained via metal-free click polymerizations of activated alkynes and azides or activated azides and alkynes. 1,5-regioregular PTAs can be produced by organic base-mediated AACP. Thiol-ene click polymerizations are versatile tools for the preparation of polythioethers with linear and hyperbranched structures. Similarly, thiol-yne click polymerizations, as the updated version of the former, can provide polythioethers and poly (vinyl sulfide)s (PVSs) with diverse structures. Novel reversible polymers can be yielded via Diels-Alder click polymerizations. Some new click polymerizations have also been researched for the synthesis of functional polymers with various structures. With these efficient polymerization techniques in hand, polymer scientists have prepared a large number of polymers with unique properties, such as luminescence, photonic patterning, adjustable light refractivity, optical nonlinearity, biodegradability, catalyst activity, self-assembly and self-healing.

Die Huang;Anjun Qin;本忠 唐

2018