Y. Mi;本忠 唐

Polymer News

2001-5

A two-channel responsive and AIE-active fluorescent probe was developed to selectively detect superoxide anions in living cells, which can be used to track the endogenous superoxide anion level when cells undergo apoptosis and inflammation.

Xiaoying Gao;Guangxue Feng;Purnima Naresh Manghnani;Fang Hu;Nan Jiang;Jianzhao Liu;Bin Liu;Jing Zhi Sun;本忠 唐

Chemical Communications

2017

Aggregation-induced/-enhanced emission (AIE/AEE) has aroused broad interest. The mechanism behind is understood as the aggregation restriction of the nonradiative decay from electronically excited state to the ground state, either through interconversion or through conical intersection, leaving the dipole-allowed radiative decay channel relatively intact. Here, a report on an AEE phenomenon for 5,10-diphenylphenazine (DPhPZ) compound is presented, for which the experiment shows to be AEE active but the lowest excited state has been long known to be “dark state,” namely with zero transition dipole with the ground state according to Kasha’s rule. The computational studies demonstrate that the optical emission stems from the “dark state” with emission intensity borrowed from higher-lying “bright state” through Herzberg–Teller vibronic coupling, and the resultant spectra are in good agreement with the experiment in terms of both line shape and peak position. The vibronic-coupling-induced radiative decay and the restricted nonradiative decay synergistically bring about highly efficient luminescence of DPhPZ in the solid phase. The findings open a new avenue for the development of solid-emissive luminophores.

Ping An Yin;Qing Wan;Yingli Niu;谦 彭;Zhiming Wang;Yuxuan Li;Anjun Qin;志刚 帅;本忠 唐

Advanced Electronic Materials

2020-7-1

We present a combined investigation by means of X-ray photoelectron spectroscopy (XPS) and near-edge X-ray absorption fine-structure (NEXAFS) spectroscopy of condensed multilayers of two polyphenylsiloles, namely hexaphenylsilole (HPS) and tetraphenylsilole (TPS). Both compounds exhibit very similar spectroscopic signatures, whose interpretation is aided by density functional theory (DFT) calculations. High-resolution XPS spectra of the Si 2p and C 1s core levels of these multilayers indicate a positively charged silicon ion flanked by two negatively charged adjacent carbon atoms in the silole core of both molecules. This result is corroborated quantitatively by DFT calculations on isolated HPS (TPS) molecules, which show a natural bond orbital partial charge of +1.67 e (+1.58 e) on the silicon and -0.34 e (-0.58 e) on the two neighbouring carbon atoms in the silole ring. These charges are conserved in direct contact with a Cu(111) substrate for films of submonolayer coverage, as evidenced by the Si 2p XPS data. The C K-edge NEXAFS spectra of HPS and TPS multilayers exhibit distinct and differing features. Their main characteristics reappear in the simulated spectra and are assigned to the different inequivalent carbon species in the molecule. The angle-dependent measurements hardly reveal any dichroism, i.e., the molecular π-systems are not uniformly oriented parallel or perpendicular with respect to the surface. Changes in the growth conditions of TPS, i.e., a reduction of the substrate temperature from 240 K to 80 K during deposition, lead to a broadening of both XPS and NEXAFS signatures, as well as an upward shift of the Si 2p and C 1s binding energies, indicative of a less ordered growth mode at low temperature.

Katharina Diller;Yong Ma;Yi Luo;Francesco Allegretti;Jianzhao Liu;本忠 唐;Nian Lin;Johannes V. Barth;Florian Klappenberger

Physical Chemistry Chemical Physics

2015

Nonlinear optical (NLO) processes in pi-electron organic and polymer systems have attracted considerable interest because their understanding has led onto many compelling technological promise as well as the discovery of new phenomena, new theoretical insights, and new materials and devices. In recent years, as the field has progressed toward technological applications, the main issues have focused on high-performance materials that comply with device manufacturing and end-use conditions. New challenges in materials synthesis are being presented. In has now been demonstrated on pilot plant scales that high-performance electro-optic polymer thin films can be routinely used in optoelectronic integrated circuit fabrication in existing microelectronic device manufacturing facilities. The key steps are standard, including spin coating, photolithography, etching, metallization, and multilayer assembly. Nanocrystal quantum dots (QDs) have been incorporated into various NLO polymers and the optical properties of the nanocomposite films have been studied by femtosecond laser Z-scan instrumentation. Nanodevices have been fabricated by UV-assisted imprinting fabrication techniques. Photonic devices based on nanomaterials and ring resonators e.g., optical switches and dispersion compensators, are discussed.

Eric Siu Wai Kong;Fang Fang;亚非 张;Shixiong Qian;本忠 唐;俊 周;晓工 王

Proceedings of SPIE - The International Society for Optical Engineering

2005

We develop a highly effective silole-infiltrated photonic crystal (PC) film fluorescence sensor with high sensitivity, good selectivity and excellent reproducibility for Fe³⁺ and Hg²⁺ ions. Hexaphenylsilole (HPS) infiltrated PCs show amplified fluorescence due to the slow photon effect of PC because the emission wavelength of HPS is at the blue band edge of the selected PC's stopband. The fluorescence can be quenched significantly by Fe³⁺/Hg²⁺ ions owing to electron transfer between HPS and metal ions. The amplified fluorescence enhances the sensitivity of detection, with a detection limit of 5 nM for Fe³⁺/Hg²⁺ ions. The sensor is negligibly responsive to other metal ions and can easily be reproduced by rinsing with pure water due to the special surface wettability of PC. As a result, a highly effective Fe³⁺/Hg²⁺ ions sensor based on HPS-infiltrated PC film has been achieved, which will be important for effective and practical detection of heavy metal ions.

Yuqi Zhang;Xiangdong Li;Loujun Gao;Jianhua Qiu;Liping Heng;本忠 唐;Lei Jiang

ChemPhysChem

2014-2-24

Circularly-polarized luminescence (CPL) has received new attention on the rise of applications to generate devices and biologically active probes. These applications require fluorophores that are not only chiral but also provide strong fluorescence intensity in aggregated state. Thus, a new research branch has opened up a few years ago, which allows CPL-active fluorophores to be emissive in aggregated-state. As a result, reports on the combination of the CPL property with the aggregation-induced emission (AIE) phenomenon have emerged. Herein the early design principles that have been reported until now to generate CPL-active AIE-active fluorophores (AIEgens) are summarized. In this regard the alignment of monomeric emitters in a chiral fashion, either in supramolecules, polymers or liquid crystals has been proven to be a successful approach. Additionally, first reports have appeared that demonstrate how to tackle the daunting task to furnish individual CPL-active AIEgens.

Jesse Roose;本忠 唐;Kam Sing Wong

Small

2016-12-21

In this paper, a new tetraphenylethene-based molecule with two carbazole-containing moieties, 1,2-bis(4-(9H-carbazol-9-yl)phenyl)-1,2-diphenylethylene (BCPD), has been successfully prepared by the McMurry coupling reaction of (4-(9H-carbazol-9-yl)phenyl)(phenyl)methanone (1). The structure of BCPD was fully characterized by elemental analysis, mass spectrometry, NMR spectroscopy and infrared spectroscopy. Its optical properties in both solution and solid-state were investigated systematically. The results show that BCPD has almost no emission in solution but is highly emissive in the aggregated form, demonstrating a typical aggregation-induced emission phenomenon. An extensive investigation of its thermal properties verifies that BCPD enjoys excellent thermal and morphological stabilities with T_d of 335 °C and T_g of 105 °C. Eventually, non-doped electroluminescence device by utilizing BCPD as emitting layer was fabricated. The device exhibits sky blue light with the maximum luminance and the maximum luminescent efficiency reaching 8624 cd m⁻² and 4.243 cd A⁻¹, respectively.

Heping Shi;Min Li;Li Fang;Xiuqing Dong;Xinlei Zhang;Huiren Peng;Shuming Chen;本忠 唐

Synthetic Metals

2016-10-1

Readily tunable systems driving the main chains of poly(phenylacetylene) (PPA) derivatives into helical conformation with desirable amount of one sense in excess were developed. With the contribution of the PPA main chain twisting, induced Cotton magnitudes were tuned by changing solvent, basicity and concentration of glycine. These agents act as tuning interferences for stabilizing or destabilizing the preferred helical structures.

Kevin Ka Leung Cheuk;Fouad Salhi;Jacky Wing Yip Lam;本忠 唐

American Chemical Society, Polymer Preprints, Division of Polymer Chemistry

2000-8

It is hard to obtain spatially ordered nanostructures via the polyion complexation process due to the inherent flexibility of polymers and isotropicity of ionic interactions. Here we report the formation of polyion assemblies with well-defined, periodically regular internal structure by imparting the proper stiffness to the molecular tile. A stiff bisligand TPE-C4-L2 was designed which is able to form a negatively charged supramolecular polyelectrolyte with transition metal ions. This supramolecular polyelectrolyte slowly self-assembled into polydispersed flat sheets with cocoon-like patterns. Upon the addition of an oppositely charged ordinary polyelectrolyte, the polydispersed cocoons immediately transformed into ultralong, uniform nanoladders as a result of matched ionic density recognition. The supramolecular polyelectrolytes assembled side-by-side, and the negative charges aligned in an array. This structure forced the positively charged polymers to lie along the negative charges so that the perpendicular arrangement of the oppositely charged chains was achieved. Such precise charge recognition will provide insight into the design of advanced materials with hierarchical self-assembled structures.

Limin Xu;Lingxiang Jiang;Markus Drechsler;Yu Sun;志荣 刘;Jianbin Huang;本忠 唐;Zhibo Li;Martien A. Cohen Stuart;云 阎

Journal of the American Chemical Society

2014-2-5