Citation: . STEREOCHEMICAL CONTROL IN PROPYLENE POLYMERIZATION CATALYZED BY UNBRIDGED METALLOCENE CATALYSTS*[J]. Chinese Journal of Polymer Science, ;2001, 19(4): 407-413.
-
Two unbridged metallocene catalysts, bis (2, 4, 7-trimethylindenyl)zirconium dichloride (met-I) and bis(2, 4, 6-trimethylindenyl) zirconium dichloride (met-II), which are different in the position o f substituents on the six-membered ringof the indenyl ligands were synthesized. The effect of substituents in the two metallocenes on the propylene polymerizationwas studied in the presence of methylaluminoxane (MAO) and triisobutylaluminium (TIBA). From the analysis ofmicrostructure determined by 13C-NMR, it was demonstrated that the polymers produced by met-II have higher [mmmm] isotactic sequences than that of met-I.Using a mechanism based on model statistical analysis,it was found that chain-end model was dominant for met-I.However,met-II obeys the concurrent two-sites model during polymerization,which can be attributed to the existence of "racemic-like"conformer in its system.
-
-
[1]
Hailong He , Wenbing Wang , Wenmin Pang , Chen Zou , Dan Peng . Double stimulus-responsive palladium catalysts for ethylene polymerization and copolymerization. Chinese Chemical Letters, 2024, 35(7): 109534-. doi: 10.1016/j.cclet.2024.109534
-
[2]
Jun Zhang , Zhiyao Zheng , Can Zhu . Stereochemical editing: Catalytic racemization of secondary alcohols and amines. Chinese Chemical Letters, 2024, 35(5): 109160-. doi: 10.1016/j.cclet.2023.109160
-
[3]
Yang Yang , Jing-Li Luo , Xian-Zhu Fu . Water-oxidation intermediates enabling electrochemical propylene epoxidation. Chinese Journal of Structural Chemistry, 2024, 43(5): 100269-100269. doi: 10.1016/j.cjsc.2024.100269
-
[4]
Min Fu , Pan He , Sen Zhou , Wenqiang Liu , Bo Ma , Shiying Shang , Yaohao Li , Ruihan Wang , Zhongping Tan . An unexpected stereochemical effect of thio-substituted Asp in native chemical ligation. Chinese Chemical Letters, 2024, 35(8): 109434-. doi: 10.1016/j.cclet.2023.109434
-
[5]
Zhongjie Li , Xiangyue Kong , Yuhao Liu , Huayu Qiu , Lingling Zhan , Shouchun Yin . Progress of additives for morphology control in organic photovoltaics. Chinese Chemical Letters, 2024, 35(6): 109378-. doi: 10.1016/j.cclet.2023.109378
-
[6]
Huangjie Lu , Yingzhe Du , Peng Lin , Jian Lin . Separation of americium from lanthanides based on oxidation state control. Chinese Journal of Structural Chemistry, 2024, 43(10): 100344-100344. doi: 10.1016/j.cjsc.2024.100344
-
[7]
Tianbo Jia , Lili Wang , Zhouhao Zhu , Baikang Zhu , Yingtang Zhou , Guoxing Zhu , Mingshan Zhu , Hengcong Tao . Modulating the degree of O vacancy defects to achieve selective control of electrochemical CO2 reduction products. Chinese Chemical Letters, 2024, 35(5): 108692-. doi: 10.1016/j.cclet.2023.108692
-
[8]
Kuangdi Luo , Yang Qin , Xuehao Zhang , Hanxu Ji , Heao Zhang , Jiangtian Li , Xianjin Xiao , Xinyu Wang . Regulable toehold lock for the effective control of strand displacement reaction sequence and circuit leakage. Chinese Chemical Letters, 2024, 35(7): 109104-. doi: 10.1016/j.cclet.2023.109104
-
[9]
Yan Liu , Yang Wang , Jiayi Zhu , Xuxian Su , Xudong Lin , Liang Xu , Xiwen Xing . Employing pH-responsive RNA triplex to control CRISPR/Cas9-mediated gene manipulation in mammalian cells. Chinese Chemical Letters, 2024, 35(9): 109427-. doi: 10.1016/j.cclet.2023.109427
-
[10]
Xue Zhao , Mengshan Chen , Dan Wang , Haoran Zhang , Guangzhi Hu , Yingtang Zhou . Ultrafine nano-copper derived from dopamine polymerization & synchronous adsorption achieve electrochemical purification of nitrate to ammonia in complex water environments. Chinese Chemical Letters, 2024, 35(8): 109327-. doi: 10.1016/j.cclet.2023.109327
-
[11]
Fei Yin , Erli Yang , Xue Ge , Qian Sun , Fan Mo , Guoqiu Wu , Yanfei Shen . Coupling WO3−x dots-encapsulated metal-organic frameworks and template-free branched polymerization for dual signal-amplified electrochemiluminescence biosensing. Chinese Chemical Letters, 2024, 35(4): 108753-. doi: 10.1016/j.cclet.2023.108753
-
[12]
Kongchuan Wu , Dandan Lu , Jianbin Lin , Ting-Bin Wen , Wei Hao , Kai Tan , Hui-Jun Zhang . Elucidating ligand effects in rhodium(Ⅲ)-catalyzed arene–alkene coupling reactions. Chinese Chemical Letters, 2024, 35(5): 108906-. doi: 10.1016/j.cclet.2023.108906
-
[13]
Long Jin , Jian Han , Dongmei Fang , Min Wang , Jian Liao . Pd-catalyzed asymmetric carbonyl alkynylation: Synthesis of axial chiral ynones. Chinese Chemical Letters, 2024, 35(6): 109212-. doi: 10.1016/j.cclet.2023.109212
-
[14]
Chen Li , Ziyuan Zhao , Shouyun Yu . Photoredox-catalyzed C-glycosylation of peptides with glycosyl bromides. Chinese Chemical Letters, 2024, 35(6): 109128-. doi: 10.1016/j.cclet.2023.109128
-
[15]
Ying-Di Hao , Zhi-Qian Lin , Xiao-Yu Guo , Jiao Liang , Can-Kun Luo , Qian-Tao Wang , Li Guo , Yong Wu . Rhodium-catalyzed Doyle-Kirmse rearrangement reactions of sulfoxoniun ylides. Chinese Chemical Letters, 2024, 35(4): 108834-. doi: 10.1016/j.cclet.2023.108834
-
[16]
Kun Tang , Fen Su , Shijie Pan , Fengfei Lu , Zhongfu Luo , Fengrui Che , Xingxing Wu , Yonggui Robin Chi . Enones from aldehydes and alkenes by carbene-catalyzed dehydrogenative couplings. Chinese Chemical Letters, 2024, 35(9): 109495-. doi: 10.1016/j.cclet.2024.109495
-
[17]
Muhammad Humayun , Mohamed Bououdina , Abbas Khan , Sajjad Ali , Chundong Wang . Designing single atom catalysts for exceptional electrochemical CO2 reduction. Chinese Journal of Structural Chemistry, 2024, 43(1): 100193-100193. doi: 10.1016/j.cjsc.2023.100193
-
[18]
Fanxin Kong , Hongzhi Wang , Huimei Duan . Inhibition effect of sulfation on Pt/TiO2 catalysts in methane combustion. Chinese Journal of Structural Chemistry, 2024, 43(5): 100287-100287. doi: 10.1016/j.cjsc.2024.100287
-
[19]
Xianxu Chu , Lu Wang , Junru Li , Hui Xu . Surface chemical microenvironment engineering of catalysts by organic molecules for boosting electrocatalytic reaction. Chinese Chemical Letters, 2024, 35(8): 109105-. doi: 10.1016/j.cclet.2023.109105
-
[20]
Pingfan Zhang , Shihuan Hong , Ning Song , Zhonghui Han , Fei Ge , Gang Dai , Hongjun Dong , Chunmei Li . Alloy as advanced catalysts for electrocatalysis: From materials design to applications. Chinese Chemical Letters, 2024, 35(6): 109073-. doi: 10.1016/j.cclet.2023.109073
-
[1]
Metrics
- PDF Downloads(0)
- Abstract views(477)
- HTML views(1)