30 results on '"Guo-Gang Shan"'
Search Results
2. An unprecedented fully reduced {MoV60} polyoxometalate: from an all-inorganic molecular light-absorber model to improved photoelectronic performance
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Xue-Xin Li, Tuo Ji, Jun-Yang Gao, Wei-Chao Chen, Ye Yuan, Hao-Yan Sha, Roland Faller, Guo-Gang Shan, Kui-Zhan Shao, Xin-Long Wang, and Zhong-Min Su
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General Chemistry - Abstract
An unprecedented fully reduced {MoV60} POM served as a cheap and robust molecular light-absorber model possessing wide light absorption and was applied to build a co-sensitized solar cell photoelectronic device.
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- 2022
3. A switchable multimode microlaser based on an AIE microsphere
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Guo-Gang Shan, Yuqin Fan, Sijie Chen, Puxiang Lai, Fengyan Song, Chunhuan Zhang, Haiyun Dong, Hui Gao, Ming-Yu Wu, and Yong Sheng Zhao
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Materials science ,Multi-mode optical fiber ,Active laser medium ,business.industry ,02 engineering and technology ,General Chemistry ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Laser ,01 natural sciences ,Fluorescence ,0104 chemical sciences ,Microsphere ,law.invention ,Wavelength ,law ,Materials Chemistry ,Optoelectronics ,Photonics ,0210 nano-technology ,business ,Preparation procedures - Abstract
Switchable multimode microlasers are of great significance to the development of photonic devices with high integration levels. Herein, we demonstrate an acid/alkaline gas-responsive multimode AIEgen@starch microsphere-based microlaser. The aggregation-induced emission (AIE) active fluorescent dye ASCPI was used as the gain medium in this study. ASCPI was weakly emissive in water but became highly emissive when introduced to a starch microsphere as a guest molecule. The resultant ASCPI@starch microsphere worked well as a typical whispering-gallery-mode microlaser. The laser mode wavelengths were size-dependent. Due to the sensitivity of ASCPI to pH, the output of the microlaser could be switched to a shorter wavelength by acetic acid vapor treatment or a longer wavelength by NH3 vapor treatment. This work will provide useful enlightenment for the rational design of effective switchable lasers using AIE materials with simple preparation procedures.
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- 2021
4. One stone, three birds: one AIEgen with three colors for fast differentiation of three pathogens
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Guo-Gang Shan, Meijuan Jiang, Jun Zhang, Jacky Wing Yip Lam, Ryan T. K. Kwok, Haotian Bai, Chengcheng Zhou, Joe H. C. Chau, Jian Du, Ben Zhong Tang, and Peng Huang
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Pathogen detection ,biology ,Chemistry ,02 engineering and technology ,General Chemistry ,Cellular level ,010402 general chemistry ,021001 nanoscience & nanotechnology ,biology.organism_classification ,01 natural sciences ,Fluorescence ,0104 chemical sciences ,Visual probe ,Biophysics ,Fluorescence microscope ,Color response ,0210 nano-technology ,Fluorescence response ,Bacteria - Abstract
Visually identifying pathogens favors rapid diagnosis at the point-of-care testing level. Here, we developed a microenvironment-sensitive aggregation-induced emission luminogen (AIEgen), namely IQ–Cm, for achieving fast discrimination of Gram-negative bacteria, Gram-positive bacteria and fungi by the naked-eye. With a twisted donor–acceptor and multi-rotor structure, IQ–Cm shows twisted intramolecular charge transfer (TICT) and AIE properties with sensitive fluorescence color response to the microenvironment of pathogens. Driven by the intrinsic structural differences of pathogens, IQ–Cm with a cationic isoquinolinium moiety and a membrane-active coumarin unit as the targeting and interacting groups selectively locates in different sites of three pathogens and gives three naked-eye discernible emission colors. Gram-negative bacteria are weak pink, Gram-positive bacteria are orange-red and fungi are bright yellow. Therefore, based on their distinctive fluorescence response, IQ–Cm can directly discriminate the three pathogens at the cell level under a fluorescence microscope. Furthermore, we demonstrated the feasibility of IQ–Cm as a visual probe for fast diagnosis of urinary tract infections, timely monitoring of hospital-acquired infection processes and fast detection of molds in the food field. This simple visualization strategy based on one single AIEgen provides a promising platform for rapid pathogen detection and point-of-care diagnosis., A simple AIEgen with three emission colors achieves rapid identification of Gram-negative bacteria, Gram-positive bacteria and fungi.
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- 2020
5. An unprecedented fully reduced {Mo
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Xue-Xin, Li, Tuo, Ji, Jun-Yang, Gao, Wei-Chao, Chen, Ye, Yuan, Hao-Yan, Sha, Roland, Faller, Guo-Gang, Shan, Kui-Zhan, Shao, Xin-Long, Wang, and Zhong-Min, Su
- Abstract
Fully reduced polyoxometalates are predicted to give rise to a broad and strong absorption spectrum, suitable energy levels, and unparalleled electronic and optical properties. However, they are not available to date. Here, an unprecedented fully reduced polyoxomolybdate cluster, namely Na
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- 2021
6. Fluorescence Imaging and Photodynamic Inactivation of Bacteria Based on Cationic Cyclometalated Iridium(III) Complexes with Aggregation-Induced Emission Properties
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Guo-Gang Shan, Wai Yeung Wong, Chuen Kam, Po-Yu Ho, Sin-Ying Lee, Yuning Hong, Sijie Chen, and Junfei Zhu
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Denticity ,medicine.medical_treatment ,Optical Imaging ,Biomedical Engineering ,Rational design ,Cationic polymerization ,Pharmaceutical Science ,chemistry.chemical_element ,Photodynamic therapy ,Photochemistry ,Gram-Positive Bacteria ,Iridium ,Fluorescence ,Anti-Bacterial Agents ,Biomaterials ,chemistry ,Gram-Negative Bacteria ,medicine ,Structural isomer ,Molecule - Abstract
Antibacterial photodynamic therapy (PDT) is one of the emerging methods for curbing multidrug-resistant bacterial infections. Effective fluorescent photosensitizers with dual functions of bacteria imaging and PDT applications are highly desirable. In this study, three cationic and heteroleptic cyclometalated Ir(III) complexes with the formula of [Ir(CˆN)2 (NˆN)][PF6 ] are prepared and characterized. These Ir(III) complexes named Ir(ppy)2 bP, Ir(1-pq)2 bP, and Ir(2-pq)2 bP are comprised of three CˆN ligands (i.e., 2-phenylpyridine (ppy), 1-phenylisoquinoline (1-pq), and 2-phenylquinoline (2-pq)) and one NˆN bidentate co-ligand (bP). The photophysical characterizations demonstrate that these Ir(III) complexes are red-emitting, aggregation-induced emission active luminogens. The substitution of phenylpyridine with phenylquinoline isomers in the molecules greatly enhances their UV and visible-light absorbance as well as the photoinduced reactive oxygen species (ROS) generation ability. All three Ir(III) complexes can stain both Gram-positive and Gram-negative bacteria efficiently. Interestingly, even though Ir(1-pq)2 bP and Ir(2-pq)2 bP are constitutional isomers with very similar structures and similar ROS generation ability in buffer, the former eradicates bacteria much more effectively than the other through white light-irradiated photodynamic inactivation. This work will provide valuable information on the rational design of Ir(III) complexes for fluorescence imaging and efficient photodynamic inactivation of bacteria.
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- 2021
7. Highly efficient singlet oxygen generation, two-photon photodynamic therapy and melanoma ablation by rationally designed mitochondria-specific near-infrared AIEgens
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Zheng Zheng, Haixiang Liu, Shaodong Zhai, Jacky Wing Yip Lam, Guo-Gang Shan, Xianglong Hu, Chao Ma, Ryan T. K. Kwok, Kam Sing Wong, Ben Zhong Tang, Ian D. Williams, Herman H. Y. Sung, and Haoke Zhang
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Fluorescence-lifetime imaging microscopy ,Biocompatibility ,Chemistry ,Singlet oxygen ,medicine.medical_treatment ,Photodynamic therapy ,General Chemistry ,Molecular engineering ,chemistry.chemical_compound ,Two-photon excitation microscopy ,In vivo ,Cancer cell ,Biophysics ,medicine - Abstract
Photosensitizers (PSs) with multiple characteristics, including efficient singlet oxygen (1O2) generation, cancer cell-selective accumulation and subsequent mitochondrial localization as well as near-infrared (NIR) excitation and bright NIR emission, are promising candidates for imaging-guided photodynamic therapy (PDT) but rarely concerned. Herein, a simple rational strategy, namely modulation of donor–acceptor (D–A) strength, for molecular engineering of mitochondria-targeting aggregation-induced emission (AIE) PSs with desirable characteristics including highly improved 1O2 generation efficiency, NIR emission (736 nm), high specificity to mitochondria, good biocompatibility, high brightness and superior photostability is demonstrated. Impressively, upon light irradiation, the optimal NIR AIE PS (DCQu) can generate 1O2 with efficiency much higher than those of commercially available PSs. The excellent two-photon absorption properties of DCQu allow two-photon fluorescence imaging of mitochondria and subsequent two-photon excited PDT. DCQu can selectively differentiate cancer cells from normal cells without the aid of extra targeting ligands. Upon ultralow-power light irradiation at 4.2 mW cm−2, in situ mitochondrial photodynamic activation to specifically damage cancer cells and efficient in vivo melanoma ablation are demonstrated, suggesting superior potency of the AIE PS in imaging-guided PDT with minimal side effects, which is promising for future precision medicine., Mitochondria-targeted photosensitizers with highly efficient singlet oxygen generation, bright near-infrared AIE and good two-photon absorption are obtained through ingenious molecular engineering for cancer cell-selective photodynamic therapy.
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- 2021
8. Inside Front Cover: Revisiting an ancient inorganic aggregation‐induced emission system: An enlightenment to clusteroluminescence
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Guo-Gang Shan, Youhong Tang, Javad Tavakoli, Yu Xiong, Zheng Zhao, Xuepeng Zhang, Jacky Wing Yip Lam, Bolong Huang, Zhaoxun Yu, Ben Zhong Tang, Tsz Shing Cheung, Jianyu Zhang, Chen Peng, and Zaiyu Wang
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Front cover ,Materials science ,media_common.quotation_subject ,Enlightenment ,Astronomy ,General Medicine ,Aggregation-induced emission ,media_common - Published
- 2021
9. Revisiting an ancient inorganic aggregation‐induced emission system: An enlightenment to clusteroluminescence
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Bolong Huang, Jacky Wing Yip Lam, Yu Xiong, Guo-Gang Shan, Jianyu Zhang, Zheng Zhao, Xuepeng Zhang, Javad Tavakoli, Chen Peng, Tsz Shing Cheung, Zhaoxun Yu, Youhong Tang, Ben Zhong Tang, and Zaiyu Wang
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Materials science ,General Medicine ,Radioluminescence ,Aggregation-induced emission ,Photochemistry - Published
- 2021
10. Enhanced 1.54-μm photo- and electroluminescence based on a perfluorinated Er(III) complex utilizing an iridium(III) complex as a sensitizer
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Hongfei Li, Jelena Gorbaciova, William P. Gillin, Chen Lyu, Huanqing Ye, Xiao-Qi Liu, Guo-Gang Shan, Li-Li Wen, and Peter B. Wyatt
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lcsh:Applied optics. Photonics ,Materials science ,chemistry.chemical_element ,02 engineering and technology ,Electroluminescence ,010402 general chemistry ,7. Clean energy ,01 natural sciences ,Article ,Erbium ,OLED ,lcsh:QC350-467 ,Iridium ,Organic LEDs ,business.industry ,lcsh:TA1501-1820 ,Chromophore ,021001 nanoscience & nanotechnology ,Atomic and Molecular Physics, and Optics ,0104 chemical sciences ,Electronic, Optical and Magnetic Materials ,chemistry ,Optics and photonics ,Optoelectronics ,Light emission ,0210 nano-technology ,business ,Luminescence ,Phosphorescence ,lcsh:Optics. Light - Abstract
Advanced 1.5-µm emitting materials that can be used to fabricate electrically driven light-emitting devices have the potential for developing cost-effective light sources for integrated silicon photonics. Sensitized erbium (Er3+) in organic materials can give bright 1.5-µm luminescence and provide a route for realizing 1.5-µm organic light emitting diodes (OLEDs). However, the Er3+ electroluminescence (EL) intensity needs to be further improved for device applications. Herein, an efficient 1.5-µm OLED made from a sensitized organic Er3+ co-doped system is realized, where a “traditional” organic phosphorescent molecule with minimal triplet–triplet annihilation is used as a chromophore sensitizer. The chromophore provides efficient sensitization to a co-doped organic Er3+ complex with a perfluorinated-ligand shell. The large volume can protect the Er3+ 1.5-µm luminescence from vibrational quenching. The average lifetime of the sensitized Er3+ 1.5-µm luminescence reaches ~0.86 ms, with a lifetime component of 2.65 ms, which is by far the longest Er3+ lifetime in a hydrogen-abundant organic environment and can even compete with that obtained in the fully fluorinated organic Er3+ system. The optimal sensitization enhances the Er3+ luminescence by a factor of 1600 even with a high concentration of the phosphorescent molecule, and bright 1.5-µm OLEDs are obtained., Light emission: Erbium and iridium make a powerful combination Light emission from ions of the element erbium, for use in electrically driven light-emitting devices, can be significantly enhanced by adding sensitizer materials containing iridium ions. The potential of erbium for cost-effective light emission in photonics applications is well-recognized, but methods to increase the power efficiency of the devices are keenly sought. Hong-Fei Li and colleagues at Queen Mary University of London, UK, and Northeast Normal University in Changchun, China, found that a phosphorescent iridium complex enhanced the emission from an erbium complex by a factor of up to 1600. The dramatic effect of the iridium sensitizer was demonstrated in an organic (carbon-based) light-emitting diode. This innovation emphasizes the potential advantages of exploring combinations of molecular complexes in light-emitting devices, rather than seeking a single light-emitting molecule possessing all of the properties required.
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- 2019
11. Fluorescence Imaging and Photodynamic Inactivation of Bacteria Based on Cationic Cyclometalated Iridium(III) Complexes with Aggregation‐Induced Emission Properties (Adv. Healthcare Mater. 24/2021)
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Po‐Yu Ho, Sin‐Ying Lee, Chuen Kam, Junfei Zhu, Guo‐Gang Shan, Yuning Hong, Wai‐Yeung Wong, and Sijie Chen
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Biomaterials ,Biomedical Engineering ,Pharmaceutical Science - Published
- 2021
12. A typical 2D covalent organic polymer as multifunctional sensor and assemble a WLED
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Guo-Gang Shan, Xin-Long Wang, Li Chen, Zhong-Min Su, Afifa Yousaf, Guan-Yu Ding, Han Zhang, and Chun-Yi Sun
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chemistry.chemical_classification ,Organic polymer ,Materials science ,Nanotechnology ,02 engineering and technology ,Polymer ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,01 natural sciences ,Blue emission ,0104 chemical sciences ,Electronic, Optical and Magnetic Materials ,Inorganic Chemistry ,chemistry ,Covalent bond ,Materials Chemistry ,Ceramics and Composites ,White light ,Physical and Theoretical Chemistry ,0210 nano-technology ,Luminescence - Abstract
Luminescent sensors have received extensive attention due to their fast-response and easy-operation and when integrating multifunctions in a sensor, the cost will be reduced substantially. Covalent organic polymers (COPs) as multifunctional luminescent sensor with outstanding performance are still underexplored. In this work, a typical COP named as COP-2 show preponderant performance in the detection of Fe3+, MnO4−, and TNP. COP-2 has the highly efficient ability to selectively detect Fe3+ among the other metal ions, and the limit of the detection (LOD) is 0.89 μM, which outperforms the reported covalent organic materials. Anion sensing shows the COP-2 has the highly anti-interference ability and recyclicity to detect MnO4−. Explosive analogs sensing demonstrates that COP-2 owns the superior ability in sensing TNP in the knockdown concentration with 0.0067 ppm LOD, which superior to the values in the reported literature. In addition to the above superb sensing performance, COP-2 can be utilized as a white light-emitting diode (WLED) when combined with the commercial blue emission LED and presents a Commission Internationale de l’Eclairage (CIE) coordinate of (0.31, 0.32). These results show the COP-2 not only has an appealing performance in multifunctional luminescent sensing application, but also has a possible application in white light emitting.
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- 2021
13. A neutral dinuclear Ir(<scp>iii</scp>) complex for anti-counterfeiting and data encryption
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Zhong-Min Su, Weilong Che, Dongxia Zhu, Martin R. Bryce, Yingjie Liu, Guo-Gang Shan, Bin Xu, Guangfu Li, and Yang Jiang
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Materials science ,Schiff base ,business.industry ,Metals and Alloys ,Nanotechnology ,02 engineering and technology ,General Chemistry ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Encryption ,Photochemistry ,01 natural sciences ,Catalysis ,0104 chemical sciences ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,chemistry.chemical_compound ,chemistry ,Materials Chemistry ,Ceramics and Composites ,Aggregation-induced emission ,0210 nano-technology ,business ,Luminescence - Abstract
A neutral dinuclear Ir(iii) Schiff base complex PIBIP has been synthesized and shown to exhibit both piezochromic luminescence (PCL) and aggregation induced emission (AIE) behaviour. An efficient second-level anti-counterfeit trademark and a data encryption device were fabricated using PIBIP as the active material.
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- 2017
14. Retraction: Sublimable cationic Ir(<scp>iii</scp>) phosphor using chlorine as a counterion for high-performance monochromatic and white OLEDs
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Zhong-Min Su, Guo-Gang Shan, Wenfa Xie, Li-Li Wen, Chun-Xiu Zang, Haizhu Sun, Hui-Ting Mao, and Lei Ding
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chemistry.chemical_classification ,Materials science ,Metals and Alloys ,Cationic polymerization ,chemistry.chemical_element ,Phosphor ,02 engineering and technology ,General Chemistry ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Photochemistry ,01 natural sciences ,Catalysis ,0104 chemical sciences ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,chemistry ,Materials Chemistry ,Ceramics and Composites ,OLED ,Chlorine ,Monochromatic color ,Counterion ,0210 nano-technology - Abstract
Retraction of ‘Sublimable cationic Ir(iii) phosphor using chlorine as a counterion for high-performance monochromatic and white OLEDs’ by Lei Ding et al., Chem. Commun., 2018, 54, 11761–11764.
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- 2020
15. Tuning Organelle Specificity and Photodynamic Therapy Efficiency by Molecular Function Design
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Hang Zou, Lei Zheng, Ryan T. K. Kwok, Jacky W. Y. Lam, Zheng Zhao, Ben Zhong Tang, Zhiyang Liu, Guo-Gang Shan, and Pengfei Zhang
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Free Radicals ,medicine.medical_treatment ,General Physics and Astronomy ,Nanotechnology ,Photodynamic therapy ,02 engineering and technology ,010402 general chemistry ,01 natural sciences ,Fluorescence ,stomatognathic system ,Molecular function ,Cell Line, Tumor ,medicine ,Humans ,General Materials Science ,Aggregation-induced emission ,Organelles ,Photosensitizing Agents ,Chemistry ,General Engineering ,021001 nanoscience & nanotechnology ,eye diseases ,0104 chemical sciences ,stomatognathic diseases ,Intersystem crossing ,Photochemotherapy ,Reactive oxygen species generation ,Reactive Oxygen Species ,0210 nano-technology ,HeLa Cells - Abstract
Efficient organic photosensitizers (PSs) have attracted much attention because of their promising applications in photodynamic therapy (PDT). However, guidelines on their molecular design are rarely reported. In this work, a series of PSs are designed and synthesized based on a triphenylamine-azafluorenone core. Their structure-property-application relationships are systematically studied. Cationization is an effective strategy to enhance the PDT efficiency of PSs by targeting mitochondria. From the molecularly dispersed state to the aggregate state, the fluorescence and the reactive oxygen species generation efficiency of PSs with aggregation-induced emission (AIE) increase due to the restriction of the intramolecular motions and enhancement of intersystem crossing. Cationized mitochondrion-targeting PSs show higher PDT efficiency than that of nonionized ones targeting lipid droplets. The ability of AIE PSs to kill cancer cells can be further enhanced by combination of PDT with radiotherapy. Such results should trigger research enthusiasm for designing and synthesizing AIE PSs with better PDT efficiency and properties.
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- 2019
16. Low efficiency roll-off and high performance OLEDs employing alkyl group modified iridium(<scp>iii</scp>) complexes as emitters
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Zhong-Min Su, Wenfa Xie, Jing Yu, Guo-Gang Shan, Li-Li Wen, and Haizhu Sun
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Materials science ,business.industry ,General Chemical Engineering ,Doping ,Analytical chemistry ,chemistry.chemical_element ,02 engineering and technology ,General Chemistry ,Electroluminescence ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,0104 chemical sciences ,chemistry ,OLED ,Optoelectronics ,Iridium ,0210 nano-technology ,business ,Phosphorescence ,Electrical efficiency ,Diode ,Common emitter - Abstract
Significant efficiency roll-off of phosphorescent organic light-emitting diodes (PHOLEDs) is a long-standing issue that limits their wider application. To address this problem, four iridium(III) complexes modified by methyl or tert-butyl groups were designed and synthesized, denoted as Me-Ir-PI, tBu-Ir-PI, Me-Ir-PB, and tBu-Ir-PB. Their photophysical, electrochemical, and electroluminescent properties were studied in detail. The electroluminescent performances of devices based on tBu-Ir-PI and tBu-Ir-PB were better than those based on Me-Ir-PI and Me-Ir-PB. The best performance was achieved by the doped device employing tBu-Ir-PI as the emitter with maximum current efficiency of 42.0 cd A−1 and maximum power efficiency of 27.0 lm W−1. Even at a practical brightness of 1000 cd m−2, the current efficiency and power efficiency remained as high as 39.2 cd A−1 and 22.3 lm W−1. Notably, all doped devices exhibited low efficiency roll-off, especially for device incorporation of tBu-Ir-PB as the guest emitter, which had extremely low roll-off of 0.9%. Meanwhile, non-doped devices based on these iridium(III) complexes also displayed good EL performances.
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- 2016
17. A facile strategy for realizing room temperature phosphorescence and single molecule white light emission
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Xiaoyan Zheng, Qian Peng, Xiaobo Huang, Ben Zhong Tang, Huili Ma, Zhigang Shuai, Xinggui Gu, Simon H. P. Sung, Guo-Gang Shan, Jacky Wing Yip Lam, and Jianguo Wang
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Materials science ,Science ,Iodide ,General Physics and Astronomy ,02 engineering and technology ,010402 general chemistry ,Photochemistry ,01 natural sciences ,Article ,General Biochemistry, Genetics and Molecular Biology ,Ion ,law.invention ,chemistry.chemical_compound ,Bromide ,law ,Atom ,Molecule ,Crystallization ,lcsh:Science ,chemistry.chemical_classification ,Multidisciplinary ,General Chemistry ,Polymer ,021001 nanoscience & nanotechnology ,0104 chemical sciences ,chemistry ,lcsh:Q ,0210 nano-technology ,Phosphorescence - Abstract
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., The demonstration of pure organic room temperature phosphorescence (RTP) luminogens with complementary emission is a key requirement for developing low-cost white light emitters. Here, the authors construct RTP-active organic salt compounds by exchanging the counterion with a heavy halide ion.
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- 2018
18. Facile Multicomponent Polymerizations toward Unconventional Luminescent Polymers with Readily Openable Small Heterocycles
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Nelson L. C. Leung, Haiqin Deng, Zheng Zhao, Mark R. J. Elsegood, Ben Zhong Tang, Hang Zou, Jacky W. Y. Lam, Ting Han, Guo-Gang Shan, Haoke Zhang, and Zijie Qiu
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chemistry.chemical_classification ,Chemistry ,Azetidine ,02 engineering and technology ,General Chemistry ,Polymer ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,Biochemistry ,Combinatorial chemistry ,Catalysis ,0104 chemical sciences ,Amidine ,chemistry.chemical_compound ,Colloid and Surface Chemistry ,Monomer ,Polymerization ,Atom economy ,Amide ,Functional polymers ,0210 nano-technology - Abstract
Heterocyclic polymers have gained enormous attention for their unique functionalities and wide applications. In contrast with the well-studied polymer systems with five- or six-membered heterocycles, functional polymers with readily openable small-ring heterocycles have rarely been explored due to their large synthetic difficulty. Herein, a facile one-pot multicomponent polymerization to such polymers is developed. A series of functional polymers with multisubstituted and heteroatom-rich azetidine frameworks are efficiently generated at room temperature in high atom economy from handy monomers. The four-membered azetidine rings in the polymer skeletons can be easily transformed into amide and amidine moieties via a fast and efficient acid-mediated ring-opening reaction, producing brand-new polymeric materials with distinctive properties. All the as-prepared azetidine-containing polymers exhibit intrinsic visible luminescence in the solid state under long-wavelength UV irradiation even without conventionally conjugated structures. Such unconventional luminescence is attributed to the clusteroluminogens formed by through-space electronic interactions of heteroatoms and phenyl rings. All the obtained polymers show excellent optical transparency, high and tunable refractive indices, low optical dispersions and good photopatternability, which make them promising materials in various advanced electronic and optoelectronic devices. The ring-opened polymers can also function as a lysosome-specific fluorescent probe in biological imaging.
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- 2018
19. A pillar-layer MOF for detection of small molecule acetone and metal ions in dilute solution
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Guo-Gang Shan, Qing-Yun Lu, Si-Quan Jiang, Shuping Zhuo, Zi-Yan Zhou, Hai-Ning Wang, and Zhong-Min Su
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Solvent ,chemistry.chemical_compound ,chemistry ,General Chemical Engineering ,Metal ions in aqueous solution ,Inorganic chemistry ,Acetone ,Molecule ,General Chemistry ,Luminescence ,Small molecule ,Layer (electronics) ,Ion - Abstract
A pillar-layer MOFs Cd(5-aip)L·3DMA (1) has been obtained under solvothermal conditions. 1 possesses non-interpenetrating pillar-layer framework with 1D rectangular-shape channels. The experimental results show that the luminescent intensity of 1 is highly dependent on metal ions and small solvent molecules, particularly Ni2+/Cd2+ ions and acetone.
- Published
- 2015
20. Unveiling photophysical properties of cyclometalated iridium(<scp>iii</scp>) complexes with azadipyrromethene and dipyrromethene ancillary: a theoretical perspective
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Guo-Gang Shan, Xin-Yao Ren, Zhong-Min Su, Yong Wu, Yun Geng, and Li Wang
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Azadipyrromethene ,chemistry.chemical_compound ,chemistry ,Band gap ,Ligand ,General Chemical Engineering ,Excited state ,Energy level splitting ,Substituent ,Quantum yield ,Density functional theory ,General Chemistry ,Photochemistry - Abstract
A density functional theory/time-depended density functional theory was used to investigate a series of heteroleptic Ir(III) complexes (1–4) employing azadipyrromethene and closely related dipyrromethene derivatives as N^N ancillary ligands, in an effort to explore the underlying reasons of non-radiative behaviour of 1 and further adjust the photophysical properties by the modification of N^N ancillary ligands. The results reveal that the non-emissive phenomenon of 1 can be attributed to the weak 3ILCT character of the emissive excited state and large structure distortion, as well as the small Topt1–Sopt0 energy gap. Upon tailoring the N^N ancillary ligands, the geometry distortion of 2–4 becomes obviously smaller in comparison with 1, accordingly, the spectrum properties are also markedly affected. For instance, the enlargement of frontier molecular orbital energy gaps from 1 to 4 results in the blue-shift of their absorption and emission spectra, which is considered to be dominated by the ancillary ligand, while there is a little contribution from the Ir(III) center. Importantly, further analysis on the quantum yield (ΦPL) of these complexes also indicates a vital role of N^N ancillary ligands. It is intriguing to note that the designed complex 4 without pendant phenyl rings substituent in the ancillary ligand, possesses an efficient indirect spin-orbital coupling route, larger transition electric dipole moment (μS3), higher Topt1–Sopt0 energy gap and smaller S3–T1 splitting energy (ΔE(S3–T1)), which ensure its higher ΦPL compared to other complexes.
- Published
- 2014
21. Thermally activated delayed fluorescence in Cu(I) complexes originating from restricted molecular vibrations
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Weilong Che, Li-Kai Yan, Yun Geng, Martin R. Bryce, Dongxia Zhu, Guo-Gang Shan, Bing Yao, Baohua Zhang, Roberto S. Nobuyasu, Zhong-Min Su, Zhiyuan Xie, Guangfu Li, and Fernando B. Dias
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Chemistry ,Organic Chemistry ,02 engineering and technology ,General Chemistry ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Photochemistry ,01 natural sciences ,Fluorescence ,Catalysis ,0104 chemical sciences ,Molecular engineering ,Molecular vibration ,Molecule ,Aggregation-induced emission ,0210 nano-technology ,Luminescence ,Single crystal - Abstract
The mechanism of thermally activated delayed fluorescence (TADF) in molecules in aggregated or condensed solid states has been rarely studied and is not well understood. Nevertheless, many applications of TADF emitters are strongly affected by their luminescence properties in the aggregated state. In this study, two new isomeric tetradentate Cu(I) complexes which simultaneously show aggregation induced emission (AIE) and TADF characteristics are reported for the first time. We provide direct evidence that effectively restricting the vibrations of individual molecules is a key requisite for TADF in these two Cu(I) complexes through in-depth photophysical measurements combined with kinetic methods, single crystal analysis and theoretical calculations. These findings should stimulate new molecular engineering endeavours in the design of AIE-TADF active materials with highly emissive aggregated states.
- Published
- 2017
22. Intramolecular π Stacking in Cationic Iridium(III) Complexes with Phenyl‐Functionalized Cyclometalated Ligands: Synthesis, Structure, Photophysical Properties, and Theoretical Studies
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Guo-Gang Shan, Dongxia Zhu, Zhong-Min Su, Hong-Tao Cao, Peng Li, Martin R. Bryce, and Rukkiat Jitchati
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Luminescence ,Chemistry ,Ligand ,Stacking ,Cationic polymerization ,Light-emitting cells ,chemistry.chemical_element ,Crystal structure ,Iridium ,Photochemistry ,Inorganic Chemistry ,Density functional calculations ,Crystallography ,Photophysics ,Intramolecular force ,Octahedral molecular geometry ,Density functional theory - Abstract
The syntheses of two new heteroleptic cationic iridium complexes containing 2,6-diphenylpyridine (Hdppy) and 2,4,6-triphenylpyridine (Htppy) as the cyclometalated ligands, namely, [Ir(dppy)2phen]PF6 (1, phen = 1,10-phenanthroline) and [Ir(tppy)2phen]PF6 (2), are described. The X-ray crystal structure of 2 reveals a distorted octahedral geometry around the Ir center and close intramolecular face-to-face π–π stacking interactions between the pendant phenyl rings at the 2-position of the cyclometalated ligands and the NN ancillary ligand. This represents a new π–π stacking mode in charged Ir complexes. Complexes 1 and 2 are green photoemitters: their photophysical and electrochemical properties are interpreted with the assistance of density functional theory (DFT) calculations. These calculations also establish that the observed intramolecular interactions cannot effectively prevent the lengthening of the Ir–N bonds of the complexes in their metal-centered (3MC) states. Complexes 1 and 2 do not emit light in light-emitting electrochemical cells (LECs) under conditions in which the model compound [Ir(ppy)2phen]PF6 (3) emits strongly. This is explained by degradation reactions of the 3MC state of 1 and 2 under the applied bias during LEC operation facilitated by the enhanced distortions in the geometry of the complexes. These observations have important implications for the future design of complexes for LEC applications.
- Published
- 2014
23. Efficient greenish-blue phosphorescent iridium(III) complexes containing carbene and triazole chromophores for organic light-emitting diodes
- Author
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Wenfa Xie, Hong Li, Guo-Gang Shan, Haizhu Sun, Dongxia Zhu, Yongming Yin, Zhong-Min Su, Hong-Tao Cao, and Li Wang
- Subjects
Dopant ,Organic Chemistry ,chemistry.chemical_element ,Phosphor ,Chromophore ,Photochemistry ,Biochemistry ,Inorganic Chemistry ,chemistry.chemical_compound ,chemistry ,Pyridine ,Materials Chemistry ,OLED ,Iridium ,Physical and Theoretical Chemistry ,Phosphorescence ,Carbene - Abstract
Two heteroleptic iridium(III) complexes using carbene as cyclometalated ligands and pyridine-triazole as ancillary ligand, namely (fpmi)2Ir(mtzpy) (1) and (fpmi)2Ir(phtzpy) (2) [fpmi = 1-(4-fluorophenyl)-3-methylimdazolin-2-ylidene-C,C2′, mtzpy = 2-(5-methyl-2H-1,2,4-triazol-3-yl)pyridine, phtzpy = 2-(5-phenyl-2H-1,2,4-triazol-3-yl)pyridine], were synthesized and their structural, photophysical and electrochemical properties investigated systematically. Both complexes exhibit bright greenish-blue phosphorescence (λmax ∼490 nm) with quantum yields of about 0.50. Comprehensive density functional theory (DFT) approach was then performed to gain insights into their photophysical and electrochemical characters. The fabrication of organic light-emitting diodes (OLEDs), employing complexes 1 and 2 as phosphorescent dopants, was successfully achieved. Among them, the device based on 1 exhibited considerable power efficiency (ηp) of 11.43 lm W−1 and current efficiency (ηc) of 11.78 cd A−1. With the merit of intrinsic characteristic of complex 1, a white OLED comprised of 1 and one orange phosphor (pbi)2Ir(biq) achieved a peak ηp of 9.95 lm W−1 and ηc of 10.81 cd A−1, together with Commission Internationale de l'Eclairage (CIE) coordinates of (0.34, 0.40). The results indicate that two iridium(III) complexes reported here are promising phosphorescent dyes for OLEDs.
- Published
- 2014
24. Large Size Color-tunable Electroluminescence from Cationic Iridium Complexes-based Light-emitting Electrochemical Cells
- Author
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Guo-Gang Shan, Qunying Zeng, Tailiang Guo, Fushan Li, and Zhong-Min Su
- Subjects
Multidisciplinary ,Fabrication ,Materials science ,business.industry ,Cationic polymerization ,chemistry.chemical_element ,02 engineering and technology ,Electroluminescence ,engineering.material ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,Article ,0104 chemical sciences ,Roll-to-roll processing ,Electrochemical cell ,chemistry ,Coating ,engineering ,Optoelectronics ,Iridium ,0210 nano-technology ,business ,Large size - Abstract
Solution-processable light-emitting electrochemical cells (LECs) with simple device architecture have become an attractive candidate for application in next generation lighting and flat-panel displays. Herein, single layer LECs employing two cationic Ir(III) complexes showing highly efficient blue-green and yellow electroluminescence with peak current efficiency of 31.6 cd A−1 and 40.6 cd A−1, respectively, have been reported. By using both complexes in the device, color-tunable LECs with a single spectral peak in the wavelength range from 499 to 570 nm were obtained by varying their rations. In addition, the fabrication of efficient LECs was demonstrated based on low cost doctor-blade coating technique, which was compatible with the roll to roll fabrication process for the large size production. In this work, for the first time, 4 inch LEC devices by doctor-blade coating were fabricated, which exhibit the efficiencies of 23.4 cd A−1 and 25.4 cd A−1 for the blue-green and yellow emission, respectively. The exciting results indicated that highly efficient LECs with controllable color could be realized and find practical application in large size lighting and displays.
- Published
- 2016
25. Synthesis, structure and photophysical properties of cationic Ir(III) complexes with functionalized 1,10-phenanthroline ancillary ligands
- Author
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Guo-Gang Shan, Yi Liao, Zhong-Min Su, Hong-Tao Cao, Dongxia Zhu, and Hai-Bin Li
- Subjects
Steric effects ,Photoluminescence ,Phenanthroline ,Organic Chemistry ,Intermolecular force ,Cationic polymerization ,Photochemistry ,Biochemistry ,Electrochemical cell ,Inorganic Chemistry ,chemistry.chemical_compound ,chemistry ,Polymer chemistry ,Materials Chemistry ,Surface modification ,Thermal stability ,Physical and Theoretical Chemistry - Abstract
A series of substituted phenanthroline ancillary ligands with different degrees of steric hindrance, namely, 4,7-di(1H-pyrrol-1-yl)-1,10-phenanthroline (L1), 4,7-di(1H-indol-1-yl)-1,10-phenanthroline ( L2 ) and 4,7-di(9H-carbazol-9-yl)-1,10-phenanthroline ( L3 ), were synthesized in order to prepare cationic Ir(III) complexes. The results of photophysical studies revealed that functionalization with higher degree of steric hindrance L3 led to significant improvement of photoluminescence quantum yields (PLQYs) in neat film for these Ir(III) complexes, which may be attributed to the decrease of the intermolecular interactions. The mechanism of photophysical properties were rationalized with the help of quantum chemical calculations. Moreover, the complexes with L3 as ancillary ligands possessed good thermal stability, indicating their potential application as candidate for light-emitting electrochemical cells (LECs).
- Published
- 2012
26. Anion-specific aggregation induced phosphorescence emission (AIPE) in an ionic iridium complex in aqueous media
- Author
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Zhong-Min Su, Guo-Gang Shan, Li-Kai Yan, Wei Guan, Dongxia Zhu, Xiaojuan Zhu, Shuang Du, Martin R. Bryce, Andrew P. Monkman, and Guangfu Li
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chemistry.chemical_classification ,Aqueous medium ,Inorganic chemistry ,Metals and Alloys ,Ionic bonding ,chemistry.chemical_element ,General Chemistry ,Photochemistry ,Highly selective ,Catalysis ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,Ion ,chemistry ,Materials Chemistry ,Ceramics and Composites ,Iridium ,Counterion ,Phosphorescence - Abstract
Efficient aggregation induced phosphorescence emission (AIPE) of an ionic Ir(iii) complex occurs when the counterion (PF6(-)) is exchanged specifically by ClO4(-) in aqueous media. As a result, a rapid, highly selective "turn-on" phosphorescent response to ClO4(-) is observed in aqueous media. These studies pave the way for a new efficient phosphorescence-based detection strategy for anions.
- Published
- 2015
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27. New ionic dinuclear Ir(III) Schiff base complexes with aggregation-induced phosphorescent emission (AIPE)
- Author
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Guo-Gang Shan, Guangfu Li, Zhong-Min Su, Yong Wu, Dongxia Zhu, Martin R. Bryce, Li-Kai Yan, Bai-Qiao Song, and Weilong Che
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Models, Molecular ,Spectrometry, Mass, Electrospray Ionization ,Schiff base ,Luminescence ,Luminescent Agents ,Metals and Alloys ,Ionic bonding ,General Chemistry ,Photochemistry ,Iridium ,Ligands ,Catalysis ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,chemistry.chemical_compound ,chemistry ,X-Ray Diffraction ,Materials Chemistry ,Ceramics and Composites ,Phosphorescence ,Schiff Bases ,Chelating Agents - Abstract
Two new ionic dinuclear Ir(III) Schiff base complexes which are straightforward to synthesise have luminescence quantum yields as high as 37% in neat films. These are the first examples of dinuclear ionic Ir(III) complexes that display aggregation-induced phosphorescent emission (AIPE).
- Published
- 2014
28. Efficient and tunable white-light emission of metal–organic frameworks by iridium-complex encapsulation
- Author
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Han Wu, Guo-Gang Shan, Kui Zhan Shao, Peng Li, Chao Qin, Xiao Zhang, Dong Xia Zhu, Zhong Min Su, Jing Li, Chun Yi Sun, and Xin Long Wang
- Subjects
Multidisciplinary ,Materials science ,Astrophysics::High Energy Astrophysical Phenomena ,General Physics and Astronomy ,chemistry.chemical_element ,Quantum yield ,Nanotechnology ,02 engineering and technology ,General Chemistry ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Bioinformatics ,01 natural sciences ,Article ,General Biochemistry, Genetics and Molecular Biology ,0104 chemical sciences ,Encapsulation (networking) ,chemistry ,White light ,Astrophysics::Solar and Stellar Astrophysics ,Molecule ,Metal-organic framework ,Iridium ,0210 nano-technology ,Luminescence - Abstract
Metal–organic frameworks (MOFs) are well known for their tunable structure and porosity. Many studies have shown they are promising for various important applications, for which their performance can be further enhanced by encapsulating functional species, such as luminescent guest molecules, within the frameworks. Although numerous MOFs are luminescent, very few emit white light and their quantum yield is usually low. Here we report a strategy to achieve efficient white-light emission by encapsulating an iridium complex in the MOF cavity. A mesoporous blue-emitting MOF is prepared as host to encapsulate a yellow-emitting iridium complex, [Ir(ppy)2(bpy)]+. The resultant composites emit bright white light with good colour quality (for example, Commission International de I’Eclairage coordinates, colour-rendering index and correlated colour temperature of (0.31, 0.33), 84.5 and 5409 K, respectively), and high quantum yield up to 115 °C. This strategy may open new perspectives for developing high-performance energy-saving solid-state lighting materials., Although many metal–organic frameworks are luminescent, few are capable of white-light emission. Here, the authors incorporate a yellow-emitting guest molecule into the cavities of a blue-emitting metal–organic framework, and tune the composition to emit white light with relatively high quantum yield.
- Published
- 2013
29. Gadolinium complex and phosphorescent probe-modified NaDyF4 nanorods for T1- and T2-weighted MRI/CT/phosphorescence multimodality imaging
- Author
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Guo-Gang Shan, Yi Liao, Sihui Wang, Jing Zhou, and Zhigao Lu
- Subjects
Lanthanide ,Male ,Materials science ,Luminescence ,Gadolinium ,Biophysics ,chemistry.chemical_element ,Nanoparticle ,Bioengineering ,Multimodal Imaging ,Biomaterials ,Nuclear magnetic resonance ,X-Ray Diffraction ,In vivo ,medicine ,Animals ,Humans ,Nanotubes ,medicine.diagnostic_test ,Magnetic resonance imaging ,Magnetic Resonance Imaging ,chemistry ,Mechanics of Materials ,Ceramics and Composites ,Heterografts ,Nanorod ,T2 weighted ,Phosphorescence ,Tomography, X-Ray Computed ,HeLa Cells - Abstract
To compensate for the deficiencies of individual imaging modalities, lanthanide-based nanoparticles are ideal building blocks for multifunctional contrast agents. Herein, oleic acid-coated NaDyF4 nanorods (DyNPs) were synthesized by the hydrothermal method, and then coated with α-cyclodextrin (α-CD) and modified with gadolinium complex (Gd-DTPA) to obtain hydrophilic and functionalized nanoparticles (DyNPs-Gd). By loading the phosphorescent probe (iridium-complex) within the surface hydrophobic layer, the developed nanophosphors (DyNPs-Gd-Ir) could be further applied in phosphorescent cell labeling. The Dy in the host induces a high X-ray absorption ability for X-ray computed tomography (CT) and negative enhancement for T2-weighted magnetic resonance imaging (MRI), whereas positive contrast for T1-weighted MRI results from the Gd-DTPA. DyNPs-Gd-Ir has been successfully applied to T1- and T2-weighted MRI/CT in vivo. Toxicity studies demonstrated that DyNPs-Gd-Ir exhibited low toxicity to living systems. Therefore, DyNPs-Gd-Ir could be a platform for next-generation contrast agents for T1- and T2-weighted MRI/CT/phosphorescence multimodal imaging.
- Published
- 2013
30. Correction: Theoretical study and design of multifunctional phosphorescent platinum(<scp>ii</scp>) complexes containing triarylboron moieties for efficient OLED emitters
- Author
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Yong Wu, Guo-Gang Shan, Hai-Bin Li, Shui-Xing Wu, Xin-Yao Ren, Yun Geng, and Zhong-Min Su
- Subjects
General Physics and Astronomy ,Physical and Theoretical Chemistry - Abstract
Correction for ‘Theoretical study and design of multifunctional phosphorescent platinum(ii) complexes containing triarylboron moieties for efficient OLED emitters’ by Yong Wu et al., Phys. Chem. Chem. Phys., 2015, DOI: 10.1039/c4cp04919e.
- Published
- 2015
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