Article
Chemistry, Physical
Qiankun Li, Chaoqun Wang, Hongliang Mu, Zhongbao Jian
Summary: This study presents a catalyst derived from cheap materials and short synthetic pathways that exhibits superior catalytic properties in olefin polymerization, enabling the formation of high molecular weight polyethylene.
JOURNAL OF CATALYSIS
(2021)
Article
Chemistry, Inorganic & Nuclear
Jie Dong, Dandan Yang, Baiquan Wang
Summary: A series of allyl palladium and nickel complexes based on imidazo[1,5-a]pyridine sulfonate ligands were synthesized and characterized. The palladium complexes showed high activity in norbornene polymerization and copolymerization with BVE, while the nickel complexes exhibited similar activity and were more suitable for copolymerization with BVE and ABE. The steric hindrance of the substituent affected the catalytic activity of the complexes in both systems.
EUROPEAN JOURNAL OF INORGANIC CHEMISTRY
(2021)
Article
Chemistry, Physical
Lin-Yan Bao, Rong-Wan Gao, Shuang Wang, Run-Han Li, Bo Zhu, Zhong-Min Su, Wei Guan
Summary: Photoredox/transition-metal dual catalysis is an efficient method for constructing C-N bonds. However, low recovery, low utilization rate, and high cost have hindered its application and development. By utilizing zinc powder, the oxidation state of nickel was successfully regulated, achieving a catalytic cycle without light.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2022)
Article
Chemistry, Multidisciplinary
Niklas F. Both, Anke Spannenberg, Haijun Jiao, Kathrin Junge, Matthias Beller
Summary: The use of bis(NHC) manganese(I) complexes 3 as catalysts for the hydrogenation of esters was investigated. Various aromatic and aliphatic esters were successfully hydrogenated at mild temperatures and low catalyst loadings using complexes 3 with KHBEt3 as additive, highlighting the efficiency of the novel catalytic system. Additionally, the versatility of the developed catalytic system was demonstrated by the hydrogenation of other substrate classes like ketones, nitriles, N-heteroarenes, and alkenes.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Multidisciplinary
Xiaoqiang Hu, Xiaohui Kang, Zhongbao Jian
Summary: Living polymerization by suppressing chain transfer is a useful method for achieving precise control over molecular weight and structure. However, the suppression of chain transfer at high temperatures has been challenging in catalytic polymerization. In this study, the unprecedented living polymerization of ethylene at 130 degrees C is reported, with a narrow molecular weight distribution range of 1.04 to 1.08. Custom-designed alpha-diimine nickel catalysts play a key role in this breakthrough, remaining active even at 200 degrees C and enabling the formation of semi-crystalline, ultrahigh-molecular-weight polyethylene at 150 degrees C.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Inorganic & Nuclear
Muhammad Zada, Liwei Guo, Wenjuan Zhang, Yanping Ma, Tongling Liang, Wen-Hua Sun
Summary: The sterically and electronically modified cycloheptyl-fused bis(arylimino)pyridine-cobalt(II) chloride precatalysts exhibited high catalytic activities for ethylene polymerization after activation, with significant influence from the ortho-substitutions on both catalytic activity and molecular weight of the resultant polyethylene. Notably, the precatalyst Co5 (R=F) showed high activity and delivered high-molecular-weight polyethylene, demonstrating the beneficial effect of ortho-substituents alongside with dibenzocycloheptyl groups. The obtained polyethylene displayed a strictly linear structure with saturated and unsaturated (vinyl) end groups.
EUROPEAN JOURNAL OF INORGANIC CHEMISTRY
(2021)
Article
Chemistry, Multidisciplinary
Jessica R. Lamb, Christopher M. Brown, Jeremiah A. Johnson
Summary: N-Heterocyclic carbenes (NHCs) react with carbodiimides (CDIs) to form betaine adducts with tunable properties, whose stability depends on substituents on CDI nitrogens and configuration is influenced by NHC substituents. Despite being in the early stages, these adducts have been utilized as ligands for transition metals and nanoparticles, as connection points in zwitterionic polymers, and to stabilize distonic radical cations.
Article
Chemistry, Multidisciplinary
Mingxin Liu, Nguyen Le, Christopher Uyeda
Summary: Nickel catalysts promote nucleophilic cyclopropanation reactions using CH2Cl2 as a methylene source and Mn as a stoichiometric reductant. The substrate scope includes a broad range of alkenes bearing electron-withdrawing substituents, and enantioselective cyclopropanations have been developed using chiral PyBox ligands. Mechanistic studies suggest the intermediacy of a (PyBox)Ni=CH2 species and DFT models provide a rationale for the nucleophilic character of the nickel carbene and the sense of enantioinduction.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Multidisciplinary
Chaoqun Wang, Xiaohui Kang, Shengyu Dai, Fengchao Cui, Yunqi Li, Hongliang Mu, Stefan Mecking, Zhongbao Jian
Summary: An effective shielding strategy using dibenzosuberyl groups achieves protection of both apical positions of a neutral Ni-II active site, suppressing chain transfer and branch formation to produce ultrahigh molecular weight polyethylenes with a strictly linear microstructure. Key features of the catalyst include easy preparation, thermal robustness, living polymerization ability, and compatibility with THF as a polar reaction medium.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Multidisciplinary
Cristian Cavedon, Sebastian Gisbertz, Susanne Reischauer, Sarah Vogl, Eric Sperlich, John H. Burke, Rachel F. Wallick, Stefanie Schrottke, Wei-Hsin Hsu, Lucia Anghileri, Yannik Pfeifer, Noah Richter, Christian Teutloff, Henrike Mueller-Werkmeister, Dario Cambie, Peter H. Seeberger, Josh Vura-Weis, Renske M. van der Veen, Arne Thomas, Bartholomaus Pieber
Summary: We demonstrate visible-light-mediated carbon-heteroatom cross-coupling reactions using a photoactive Ni(II) precatalyst. The activation of this precatalyst involves an initial intraligand charge transfer event triggered by visible light irradiation. Additionally, a porous, recyclable organic polymer for heterogeneous nickel catalysis of cross-coupling reactions is obtained through ligand polymerization.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Multidisciplinary
Zi-Chao Wang, Pei-Pei Xie, Youjun Xu, Xin Hong, Shi-Liang Shi
Summary: The use of a bulky yet flexible chiral N-heterocyclic carbene (NHC) ligand in low-temperature Ni-catalyzed C-N cross-coupling has achieved high enantioselectivity with low barriers. Computational studies show that the rotations of multiple sigma-bonds on the chiral ligand can adapt to the changing needs of catalytic processes, making this design widely applicable to diverse transition states for challenging metal-catalyzed asymmetric cross-coupling reactions.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Multidisciplinary
Mateusz Janeta, Julius X. Heidlas, Olafs Daugulis, Maurice Brookhart
Summary: The reactivity of Ni-II and Pd-II olefin polymerization catalysts can be enhanced by introducing electron-withdrawing substituents on the supporting ligands, as demonstrated in this paper. Compared to the trifluoromethyl group, the trippy substituent shows stronger electron-withdrawing ability, leading to better performance in catalytic turnover frequency and polymer molecular weight.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Multidisciplinary
Akira Saito, Shinya Adachi, Naoya Kumagai, Masakatsu Shibasaki
Summary: The strategic use of a sterically demanding Ni-II pincer carbene complex has enabled high enantioselectivity in the direct catalytic asymmetric addition of acetonitrile to aldehydes, resulting in highly enantioenriched beta-hydroxynitriles. This highly atom-economical process offers a promising pathway for utilizing inexpensive acetonitrile as a C2 building block in practical synthetic toolbox for asymmetric catalysis.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Review
Chemistry, Inorganic & Nuclear
Sofia Friaes, Sara Realista, Henrique Mourao, Beatriz Royo
Summary: This article covers the recent progress in the use of N-heterocyclic carbenes (NHCs) in manganese and rhenium catalysis, with a focus on hydrosilylation, hydrogenation, borrowing hydrogen processes, as well as the electrochemical and photochemical reduction of CO2.
EUROPEAN JOURNAL OF INORGANIC CHEMISTRY
(2022)
Review
Chemistry, Multidisciplinary
Justus Diekamp, Thomas Seidensticker
Summary: The recycling of homogeneous catalysts in a homogeneous matrix is a challenging task for many reactions aiming for industrial applications. Although various synthetic approaches for recyclable homogeneous catalysts exist, a concise overview of catalyst modifications is lacking in the literature. This review aims to fill this gap by summarizing the existing synthesis pathways for polar, non-polar, fluorous, and molecular-weight-enlarged catalysts and examining their modular and late-stage approaches. Additionally, the potential for a generally applicable tag library to facilitate catalyst modifications for specific recycling strategies is explored.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Polymer Science
Zefan Xiao, Liu Zhong, Cheng Du, Wenbo Du, Handou Zheng, Chi Shing Cheung, Lingzhi Wang, Haiyang Gao
Summary: This study investigates the substituent effects of vinyl arene in palladium-catalyzed copolymerization with different substituted styrenes. The electronic and steric effects of substituents on the copolymerization reaction are quantitatively evaluated. Results show significant impact of substituents on turnover number, copolymer molecular weight, and stereoregularity, highlighting the positioning effects of substituents on the reaction.
Article
Chemistry, Inorganic & Nuclear
Jiongzhe Wu, Wei Li, Shanyue Guan, Xiaohong Chen, Haiyang Gao, Xiaolong Liu
Summary: In this study, Vanadium-doped NaNbO3 powder was successfully prepared by adjusting the mass ratio of Nb2O5, NaOH and V2O5 using the hydrothermal synthesis method. The photocatalytic degradation activity of Vanadium-doped NaNbO3 for antibiotics in wastewater showed promising results, suggesting its potential application in antibiotic wastewater treatment.
INORGANIC CHEMISTRY COMMUNICATIONS
(2021)
Article
Nanoscience & Nanotechnology
Cheng Du, Chi Shing Cheung, Handou Zheng, Donghui Li, Wenbo Du, Heng Gao, Guodong Liang, Haiyang Gao
Summary: This study successfully developed an efficient strategy for adjusting the emission color of nontraditional intrinsic luminescent polymers through through-space acceptor-donor charge transfer, with experiments showing that the emission color can be tuned by changing postfunctionalization conversion and monomer substituents.
ACS APPLIED MATERIALS & INTERFACES
(2021)
Article
Materials Science, Multidisciplinary
Wenjie Tao, Yusheng Zhou, Faxu Lin, Haiyang Gao, Zhenguo Chi, Guodong Liang
Summary: This study reports a new type of mechanically responsive materials, RTP polymers, which possess both mechanochromic and mechanodecay characteristics. These polymers exhibit abundant changes in fluorescence intensity, emission color, RTP intensity, and RTP lifetime under force stimuli, enabling the detection of material deformation. Through phosphorescence lifetime and image analysis, early damage warning for engineering polymers can be achieved.
ADVANCED OPTICAL MATERIALS
(2022)
Review
Polymer Science
Chi Shing Cheung, Xinbo Shi, Lixia Pei, Cheng Du, Heng Gao, Zonglin Qiu, Haiyang Gao
Summary: In this review, we introduce the present status and synthesis methods of aromatic polyketones made from vinyl arene and CO. The use of [N,N] bidentate palladium catalysts in catalytic synthesis is discussed, along with the effects of vinyl arene monomer, counteranion, and solvent on copolymerization. The stereochemistry of copolymerization is also addressed.
JOURNAL OF POLYMER SCIENCE
(2022)
Article
Polymer Science
Wenbo Du, Handou Zheng, Yinwu Li, Chi Shing Cheung, Donghui Li, Heng Gao, Huiyun Deng, Haiyang Gao
Summary: This study developed a new neutral nickel catalyst with good thermal stability and high tolerance towards polar monomers. The copolymerization reaction using this catalyst produced branched copolymers with high molecular weight and high monomer incorporation, similar to commercially prepared products. Density functional theory calculations provided insights into the mechanism of copolymer formation.
Review
Chemistry, Physical
Huiyun Deng, Handou Zheng, Heng Gao, Lixia Pei, Haiyang Gao
Summary: This review focuses on late transition metal catalysts with chelating amines for olefin polymerization. A variety of catalysts with different amine donors are surveyed, and the relationship between catalyst structure and catalytic performance is discussed. The aim is to promote the development of high-performance polyolefin materials.
Article
Polymer Science
Lingzhi Wang, Donghui Li, He Ren, Yuru Wang, Wei Wu, Yuxin Gao, Xiong Wang, Haiyang Gao
Summary: In this study, the stereospecific polymerization of 1-alkenes was investigated using nonconventional pyridylamido hafnium catalysts with different bridgehead substituents. It was found that the bridgehead substituents significantly affected the polymerization activity and molecular weight distribution of the resultant poly(4-methylpentene)s.
Article
Chemistry, Multidisciplinary
Jing Ma, Yusheng Zhou, Haiyang Gao, Fangming Zhu, Guodong Liang
Summary: Photoluminescent materials are widely used in various fields, with a recent study reporting rare full-type photoluminescence from a single organic molecule, showing properties like aggregation-induced phosphorescence and thermoresponsive persistent phosphorescence. The materials can provide multiple visual signals upon temperature variation, and their luminescence thermoresponse is amplified when incorporated into polymers. A facile method based on phosphorescence lifetime and image analysis is used for quick, visual, and quantitative temperature sensing, showing promise for applications in quantitative temperature sensing.
MATERIALS CHEMISTRY FRONTIERS
(2021)
Article
Materials Science, Multidisciplinary
Xin Li, Zhen Liu, Zekun Zhou, Haiyang Gao, Guodong Liang, Daniel Rauber, Christopher W. M. Kay, Peng Zhang
Summary: The study found that doping salts with small-sized cations can enhance the electrical conductivity of PEDOT:PSS films by improving crystalline order and p-doped levels. These findings will be beneficial in developing recipes based on PEDOT:PSS/salt composites for printed flexible electronics applications.
ACS APPLIED POLYMER MATERIALS
(2021)
Article
Chemistry, Physical
Handou Zheng, Liu Zhong, Cheng Du, Wenbo Du, Chi Shing Cheung, Jingjing Ruan, Haiyang Gao
Summary: The development of thermally robust palladium-based catalysts for (co)polymerization of ethylene and polar monomers with high activities remains a challenging task. By combining hydrogen bonding interactions with steric and electronic modifications, new dibenzobarrelene-based alpha-diimine palladium complexes with different substituents have been synthesized and characterized. Through the steric and electronic effects as well as hydrogen bonding contributions, chloro- and methoxy-substituted palladium catalysts showed excellent performance in ethylene polymerization and copolymerization with high MA incorporation, respectively.
CATALYSIS SCIENCE & TECHNOLOGY
(2021)
Article
Polymer Science
Cheng Du, Hongling Chu, Zefan Xiao, Liu Zhong, Yusheng Zhou, Wei Qin, Guodong Liang, Haiyang Gao
Article
Chemistry, Applied
Guangfu Liao, Liu Zhong, Chi Shing Cheung, Cheng Du, Jialong Wu, Wenbo Du, Handou Zheng, Haiyang Gao
MICROPOROUS AND MESOPOROUS MATERIALS
(2020)
