Article
Chemistry, Inorganic & Nuclear
Shun Ohta, Narumi Miura, Keiichiro Saitoh, Keigo Itoh, Sora Satoh, Ryo Miyamoto, Masaaki Okazaki
Summary: The study revealed a significant impact of terminal ligands on the coordination features of deprotonated 2,2'-bis(indolyl)methanes, showing flexibility in coordination modes. The synthesized dichlorido complexes exhibited high catalytic activity and selectivity in alkyne cyclotrimerization reactions, with the highest isolated yield among reactions favoring the 1,3,5-form using Ti-based catalyst systems.
Article
Chemistry, Multidisciplinary
Baokang Zou, Yipeng Zhan, Xiuli Xie, TongTong Zhang, Runkai Qiu, Fangming Zhu
Summary: Two salalen titanium complexes, one with hydrogen and one with fluorine on the phenolate ring close to the imine, were synthesized for copolymerization of ethylene with 1-octene. The fluorine-containing complex showed higher catalytic activity and better copolymer characteristics, indicating the potential of introducing fluorine substituents for improved performance in copolymerization reactions.
Article
Chemistry, Inorganic & Nuclear
Tomoyuki Toda, Takamasa Yamaguchi, Katsuhiko Takenaka
Summary: Significant advancements have been made in metallocene catalysis, thanks to the development of cyclopentadienyl (Cp) ligands. Various ligand combinations have been utilized for the development of post-metallocene catalysts in the past 20 years. This study focuses on zirconium and hafnium complexes using the 10 pi-electron cyclooctatetraenyl (Cot) dianion as a ligand, and investigates their ability to catalyze olefin polymerization.
EUROPEAN JOURNAL OF INORGANIC CHEMISTRY
(2023)
Article
Chemistry, Inorganic & Nuclear
Adway O. Zacharias, James X. Mao, Kwangho Nam, H. V. Rasika Dias
Summary: This study synthesized and studied the structures and interactions of vinyltrifluoroborate ligands in metal complexes, revealing asymmetric binding between metal and carbon, as well as the influence of supporting ligands on the binding between ligands and metals.
DALTON TRANSACTIONS
(2021)
Article
Chemistry, Inorganic & Nuclear
Majeda Al Hareri, David J. H. Emslie
Summary: The reaction of H-2(acen), H-2(cis-Cyacen) or H-2(trans-Cyacen) with [Zr(CH2SiMe3)(4)] at room temperature yielded corresponding compounds, which displayed trigonal prismatic shapes in the solid state and different stabilities and decomposition properties at different temperatures.
EUROPEAN JOURNAL OF INORGANIC CHEMISTRY
(2022)
Article
Chemistry, Applied
Xin-E Duan, Xiao-Xia Zhang, Tian Liu, Sheng-Di Bai, Hongbo Tong, Jian-Bin Chao, Wen-Hua Sun
Summary: Seven chlorozirconium complexes with different ligands and seven iron complexes were prepared and tested for ethylene polymerization, showing moderate to good activities and producing polyethylenes with high molecular weight and broad dispersity upon activation with methylaluminoxane (MAO).
APPLIED ORGANOMETALLIC CHEMISTRY
(2021)
Article
Chemistry, Inorganic & Nuclear
Mukundam Vanga, Vo Quang Huy Phan, Jiang Wu, Alvaro Munoz-Castro, H. V. Rasika Dias
Summary: Thallium(I) complexes of B-methylated and B-phenylated tris(pyridyl)borates with trifluoromethyl groups at the pyridyl ring 6-positions have been synthesized and compared to the tris(pyrazolyl)borate analogues. The coordination modes and spectroscopic features of these complexes have been studied, revealing distinct differences between the two scorpionate families. The steric demands of the ligands have been quantified using the buried volume concept. Ligand transfer chemistry from these complexes to copper(I) under ethylene has also been investigated, and computational analyses of the coordination modes have been performed.
INORGANIC CHEMISTRY
(2023)
Article
Chemistry, Organic
Qianyi Zhao, Qiu-Yue Yao, Yan-Jiao Zhang, Ting Xu, Jie Zhang, Xuenian Chen
Summary: Bis(pyrazolyl)borate complexes show high catalytic efficiency and selectivity in carbene/nitrene transfer and addition reactions.
EUROPEAN JOURNAL OF ORGANIC CHEMISTRY
(2022)
Article
Polymer Science
Feng Li, Yuhongxu Bai, Jianghao He, Tingting Song, Wei Gao, Xiaoyue Mu, Ying Mu
Summary: A series of novel Ti(IV) complexes with nonsymmetric amine-bis(phenolate) tetradentate ligands have been synthesized and characterized. These complexes exhibit moderate to high catalytic activities for ethylene polymerization and produce high molecular weight polyethylenes. They also show high catalytic activities for copolymerization reactions of propylene, 1-hexane, ethylene/1-hexene, and ethylene/1-octene, producing polyolefin thermoplastic elastomer or linear low-density polyethylene with high molecular weights and moderate to high comonomer incorporations.
Article
Polymer Science
Amjad Ali, Nadeem Muhammad, Shahid Hussain, Muhammad Imran Jamil, Azim Uddin, Tariq Aziz, Muhammad Khurram Tufail, Yintian Guo, Tiantian Wei, Ghulam Rasool, Zhiqiang Fan, Li Guo
Summary: The kinetics of ethylene and propylene polymerization catalyzed by homogeneous metallocene using different co-catalysts were studied. The results showed varying effects on polymer properties, with alkylaluminum having complex influences on molecular weight distribution of polyethylene. Additionally, the study explored the mechanistic features of zirconocenes catalyzed olefin polymerizations and chain termination mechanisms.
Article
Chemistry, Multidisciplinary
Alexander Goller, Johannes Obenauf, Winfried P. P. Kretschmer, Rhett Kempe
Summary: We reported a Coordinative Chain Transfer Polymerization catalyst for highly controlled and efficient polymerization of ethylene. The Zr catalyst demonstrated long life and temperature stability, and showed high activity with triethylaluminum as the chain transfer agent. The addition of ethylene gradually increased the chain length of the polyethylene products, and very low polydispersity was achieved with catalyst elongating alkyl chains of 60,000 or more.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Organic
Maxym Tansky, Zipeng Gu, Robert J. Comito
Summary: This report introduces a new method for the synthesis of bis(pyrazolyl)alkanes, avoiding common issues in traditional methods and suitable for systematic ligand optimization. Additionally, new reactants including pyrazoles and aldehydes have been explored, providing a new direction for the development of novel catalysts.
JOURNAL OF ORGANIC CHEMISTRY
(2021)
Article
Chemistry, Organic
Mariia M. Melero, Zuzanna Klosek, Carmen Ramirez de Arellano, Andrea Olmos
Summary: Poly(pyrazolyl)borate ligands can be synthesized by reacting highly reactive haloboranes with in situ formed pyrazolides under mild conditions. This versatile method allows for the selective synthesis of bis-, tris-, or tetrakis(pyrazolyl)borates and permits the use of previously inaccessible functional groups on the heterocyclic moieties. Additionally, bulky sodium and thallium(I) poly(pyrazolyl)borates with reduced donating ability have been obtained for the first time.
JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Crystallography
M. Mena, A. Perez-Redondo, V. Varela-Izquierdo, C. Yelamos
Summary: The crystal structures of two monopentamethylcyclopentadienylhafnium(IV) derivatives were determined by X-ray diffraction analysis. Compound I crystallizes as a dimer in the monoclinic space group C2/c, while compound II crystallizes in the monoclinic space group Cc. Compound II, a previously unknown compound, was also characterized using spectroscopic and analytical methods.
CRYSTALLOGRAPHY REPORTS
(2021)
Article
Chemistry, Inorganic & Nuclear
I. V. Skabitskii, S. S. Shapovalov
Summary: TpReOCl(2) reacts with methanol in the presence of triethylamine to form a new rhenium alkoxide complex TpReO(OMe)(2). This complex can further react with water to form a dimeric complex [TpReO(mu-O)](2). It can also react with acetic anhydride to produce a complex TpReO(OAc)(2) with terminal acetate substituents.
RUSSIAN JOURNAL OF COORDINATION CHEMISTRY
(2022)
Article
Chemistry, Multidisciplinary
Quan Wang, Zhao Zhang, Chen Zou, Changle Chen
Summary: In this study, a simple cocatalyst strategy was designed to enhance the catalytic properties of various nickel catalysts in ethylene polymerization and enable control over product morphology.
CHINESE CHEMICAL LETTERS
(2022)
Article
Polymer Science
Amir Mohammad Mansouri, Mehrsa Emami, Saleh Yousefi, Changle Chen, Mahdi Hashemzadeh Gargari, Ahad Hanifpour, Naeimeh Bahri-Laleh
Summary: This study quantified the microstructural, flow, and mechanical properties of two commercially available HDPE samples with different particle sizes. The results showed that the film grade sample had larger particle sizes and better mechanical properties compared to the blow molding sample.
JOURNAL OF APPLIED POLYMER SCIENCE
(2022)
Article
Chemistry, Multidisciplinary
Changwen Hong, Zihao Wang, Hui Jiang, Guifu Si, Maoping Song, Changle Chen
Summary: Brookhart-type α-diimine nickel and palladium catalysts have been extensively studied, but their heterogenization has received less attention. In this study, a trifluoroborate potassium substituent was introduced on an α-diimine framework. The ionic nature of trifluoroborate potassium strengthened the interaction between the α-diimine nickel complex and SiO2 support, while its electron-donating property enhanced the catalyst stability and polyethylene molecular weight.
CHINESE CHEMICAL LETTERS
(2023)
Article
Chemistry, Multidisciplinary
Zhanshan Ma, Mengli Xu, Ningning Zhu, Chen Tan, Changle Chen
Summary: Heterogenization can improve the thermal stability and product morphology control of olefin polymerization catalysts, which are important parameters for industrial polyethylene production. In this study, alpha-diimine nickel catalysts with -OH or -ONa anchoring groups were designed and prepared to enable facile heterogenization on silica. The heterogeneous catalysts exhibited enhanced thermal stabilities and high catalytic activity, resulting in improvements in polymer morphology control, catalytic activity, and polyethylene molecular weight.
CHINESE JOURNAL OF CHEMISTRY
(2023)
Article
Chemistry, Physical
Shi-Yu Chen, Yu-Hang Song, Shuang Jiao, Chen Zou, Shi-Huan Li, Changle Chen, Xiao-Bing Lu, Ye Liu
Summary: Polyethylenes are widely used synthetic polymers, and introducing functional groups into polyethylene backbone can improve environmental persistence and compatibility with other materials. However, this process is hindered by the formation of alternating polyketones. By reducing the carbonyl density in polyketones, their properties become closer to polyethylene. In this study, Ni and Pd-coordinated cationic catalysts were used for nonalternating carbonylative copolymerization of ethylene, resulting in car-bonyl functionalized polyethylenes with similar properties to commercial high-density polyethylene.
JOURNAL OF CATALYSIS
(2023)
Article
Chemistry, Multidisciplinary
Jie Li, Dan Peng, Chen Tan, Changle Chen
Summary: In this contribution, an outer-shell self-supporting strategy was designed to heterogenize nickel catalysts on different fillers via precipitation homopolymerization of ionic cluster type polar monomer. These catalysts demonstrated high activity, good product morphology control, and stable performances in ethylene polymerization and copolymerization. Moreover, various polyolefin composites with great mechanical and customized properties can be efficiently synthesized.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Inorganic & Nuclear
Yan-Bing Wang, Chenlong Nan, Weize Zhuo, Chen Zou, Hui Jiang, Xin-Qi Hao, Changle Chen, Mao-Ping Song
Summary: The introduction of O-donor groups on amine-imine ligands leads to the synthesis of a series of nickel complexes, which exhibit high catalytic activities and produce polyethylene elastomers with high molecular weight. Moreover, these nickel complexes can also catalyze the copolymerization of ethylene with various functional monomers to prepare functionalized polyolefins.
INORGANIC CHEMISTRY
(2023)
Article
Polymer Science
Somayyeh Sadat Afi Kheljani, Khadijeh Didehban, Mohammad Atai, Changle Chen, Naeimeh Bahri-Laleh
Summary: In this research, the functionalization of easily available polyalphaolefin (PAO) based resins was achieved through copolymerization and further modification. The microstructure of the synthesized and modified resins was analyzed using various analytical methods. The resulting macromer showed a hydrophilic nature and had potential applications in tissue engineering.
JOURNAL OF POLYMER RESEARCH
(2023)
Article
Polymer Science
Dan Peng, Menghe Xu, Chen Tan, Changle Chen
Summary: In this study, an emulsion polymerization strategy was used to heterogenize imino-based nickel olefin polymerization catalysts on solid supports. Polymeric microspheres were prepared through emulsion copolymerization, and the resulting heterogeneous nickel catalysts exhibited excellent properties in ethylene polymerization and copolymerization. The catalytic properties could be controlled by adjusting the comonomer type, composition, and particle size. This strategy allowed for product morphology control, avoided reactor fouling, and generated polyethylene products with minimal inorganic contamination. Furthermore, the introduction of polymer microspheres improved the mechanical and surface properties of polyolefin products.
Article
Polymer Science
Menghe Xu, Ao Chen, Wu Li, Yougui Li, Chen Zou, Changle Chen
Summary: Introducing polar biomass groups into polyolefins improves their nonpolar nature and aligns with sustainable development. Researchers have developed an efficient method to produce polar functionalized polyolefins with high biomass content. By utilizing phosphine-sulfonate palladium-catalyzed copolymerization reactions, bioresourced comonomers with oleyl and cinnamyl groups are inserted into the polyolefins.
Article
Chemistry, Physical
Jie Xu, Changle Chen, Xiangkai Kong
Summary: Controlled alloying, structure design, phase exploration, and carbon support modulation strategies are used for efficient Ru-based catalyst synthesis. A stepped annealing approach is employed to create Ru active sites, where Ru nanocrystals are in-situ formed on CuO surface and strong interaction at the interface is generated. The resultant Ru-CuO-SA catalyst exhibits high overpotential, low Tafel slope, and high turnover frequency, surpassing most reported materials. The creation of Ru-O-Cu bonds enhances surface oxophilicity and provides moderate hydrogen binding, resulting in improved hydrogen production efficiency.
Review
Chemistry, Multidisciplinary
Chen Tan, Min Chen, Changle Chen
Summary: Transition metal-catalyzed olefin-polar monomer copolymerization has the potential to synthesize polar group-functionalized polyolefin materials. However, the traditional trial-and-error approach is challenging and time-consuming. Recent 'catalyst + X' strategies have emerged, which utilize the interactions between the catalyst and other components in the copolymerization system to influence the reaction and resulting material properties. This review summarizes selected examples of these strategies and discusses future perspectives.
TRENDS IN CHEMISTRY
(2023)
Article
Chemistry, Multidisciplinary
Chen Zou, Chen Tan, Changle Chen
Summary: Polyolefins are commonly used synthetic polymers, but their limited compatibility with polar materials has hindered their application in certain fields. Transition-metal-catalyzed copolymerization of olefin and polar functionalized monomers allows for the synthesis of polar-functionalized polyolefin materials with improved properties. Heterogenization strategies for the synthesis of high-performance heterogeneous nickel catalysts have been developed, offering better control over product morphology and improved polymerization processes.
ACCOUNTS OF MATERIALS RESEARCH
(2023)
Article
Multidisciplinary Sciences
Chen Zou, Quan Wang, Guifu Si, Changle Chen
Summary: Polar bimodal polyethylene is demonstrated as a potential solution to the trade-off between catalytic activity and polymer molecular weight caused by polar groups in catalysts. Three synthetic routes are investigated to achieve high miscibility between the polar and non-polar fractions, with the co-anchoring strategy being the most effective. This produces polyolefin materials with excellent properties for various applications.
NATURE COMMUNICATIONS
(2023)
Article
Polymer Science
Daohong Liao, Wenmin Pang, Muhammad Sohail Bashir, Changle Chen
Summary: Tacticity plays a significant role in the characteristics of synthetic polymers. This study presents a tubular reactor strategy for continuous flow polymerization of isobutyl vinyl ether (IBVE), resulting in highly stereoselective poly(IBVE). The obtained poly(IBVE) product demonstrates technical advantages for potential industrial applications.
