Department of Polymer Materials, College of Materials Science and Engineering, Shanghai University, Materials Building, Nanchen Street 333, Shanghai 200444, China.
Tianjin Key Lab of Composite & Functional Materials, School of Material Science and Engineering, Tianjin University, Tianjin 300072, China.
Inorg Chem. 2023 Mar 27;62(12):4980-4989. doi: 10.1021/acs.inorgchem.3c00110. Epub 2023 Mar 14.
As indenyl-derivates, the tetrahydrofluorenyl ligands had an expanded "wingspan" with considerable steric hindrance. In this text, the rare-earth metal complexes bearing tetrahydrofluorenyl ligands have been synthesized and fully characterized by NMR (H and C) and X-ray diffraction analyses. Upon the activation by [PhC][B(CF)], all the scandium complexes exhibited excellent catalytic activity for highly syndioselective polymerization of styrene with a narrow molecular weight distribution (/ < 2.0), suggesting the beneficial influence of tetrahydrofluorenyl ligands in stabilizing the single-site active species during the polymerization. Moreover, the scandium-based catalytic systems also promoted the 1,4-regular polymerization of butadiene and its copolymerization with styrene, affording diblock copolymers featuring a highly syndiotactic polystyrene block and a 1,4-specific PBD block. The kinetics investigation revealed the huge gap in -catalyzed polymerization reactivity ratios (/ > 300) between butadiene and styrene, and this further proved the block structure of styrene-butadiene copolymers. The morphology and mechanical property of the selected diblock copolymer were, respectively, investigated by atomic force microscopy and stress-strain experiments.
作为茚基衍生物，四氢芴基配体具有扩展的“翼展”，具有相当大的空间位阻。在本文中，合成了具有四氢芴基配体的稀土金属配合物，并通过 NMR（H 和 C）和 X 射线衍射分析进行了充分表征。在[PhC][B(CF)]的活化作用下，所有钪配合物均表现出对苯乙烯高度选择性聚合的优异催化活性，分子量分布较窄（/ < 2.0），表明四氢芴基配体在聚合过程中稳定单活性物种方面具有有益影响。此外，基于钪的催化体系还促进了丁二烯的 1,4-规则聚合及其与苯乙烯的共聚，得到了具有高间规聚苯乙烯嵌段和 1,4-特异性 PBD 嵌段的嵌段共聚物。动力学研究表明，丁二烯和苯乙烯之间的-catalyzed 聚合反应活性比（/ > 300）存在巨大差距，这进一步证明了苯乙烯-丁二烯共聚物的嵌段结构。通过原子力显微镜和应力-应变实验分别研究了所选嵌段共聚物的形态和力学性能。
