The State Key Laboratory for Supramolecular Structure and Materials, School of Chemistry, Jilin University, 2699 Qianjin Street, Changchun 130012, People's Republic of China.
Dalton Trans. 2019 Sep 17;48(36):13719-13731. doi: 10.1039/c9dt03225h.
A number of new sulfur-bridged tridentate [OSO] bisphenolato-based ligand precursors S(2-CH2-4-tBu-6-R-C6H2OH)2 [R = CMe3 (H2L1), CMe2Ph (H2L2), CMePh2 (H2L3), CPh3 (H2L4), and C(p-Tol)3 (H2L5)] were synthesized by reactions of Na2S·9H2O with 2 eq. of the corresponding 2-(bromomethyl)-4-(tert-butyl)-6-R-phenol. Their neutral titanium complexes [S(2-CH2-4-tBu-6-R-C6H2O)2]TiCl2 [R = CMe3 (1), CMe2Ph (2), CMePh2 (3), CPh3 (4), and C(p-Tol)3 (5)] were synthesized in high yields by direct HCl-elimination reactions of TiCl4 with the corresponding ligand precursors in toluene. Ionic titanium complexes [NHEt3][S(2-CH2-4-tBu-6-R-C6H2O)2TiCl3] [R = CMe3 (6), CMePh2 (7)] and [NH2Et2][S(2-CH2-4-tBu-6-R-C6H2O)2TiCl3] [R = CMe3 (8) and CMePh2 (9)] were obtained in high yields from the reactions of TiCl4 with the corresponding ligand precursors in the presence of 2 eq. of triethylamine or diethylamine. Neutral zirconium complexes [S(2-CH2-4-tBu-6-R-C6H2O)2]ZrCl2(THF) [R = CMe2Ph (10·THF), and CMePh2 (11·THF)] were synthesized by reactions of ZrCl4 with 1 eq. of the dilithium salt of the corresponding ligand precursors Li2L in THF. The new titanium and zirconium complexes were characterized by 1H and 13C NMR, IR and elemental analyses. The molecular structures of complexes 4, 6 and 10·THF were determined by single-crystal X-ray diffraction analysis. The X-ray crystallography analysis reveals that titanium complex 4 has a five-coordinating environment surrounding the central metal atom, while the titanium complex 6 and the THF-solvated zirconium complex 10·THF possess a six-coordinating pseudo-octahedral environment around the central metal atom. Upon activation with MAO or AliBu3/Ph3CB(C6F5)4, all these titanium and zirconium complexes exhibit moderate to high catalytic activities for ethylene polymerization and ethylene/1-hexene copolymerization with moderate to high comonomer incorporation, and the ionic titanium complexes 6, 7, 8 and 9 show lower catalytic activity than their corresponding neutral complexes under similar conditions.
一系列新的硫桥三联体[OSO]双酚基配体前体 S(2-CH2-4-tBu-6-R-C6H2OH)2 [R = CMe3 (H2L1)、CMe2Ph (H2L2)、CMePh2 (H2L3)、CPh3 (H2L4)和 C(p-Tol)3 (H2L5)] 通过 Na2S·9H2O 与相应的 2-(溴甲基)-4-(叔丁基)-6-R-苯酚的 2 eq 反应合成。它们的中性钛配合物[S(2-CH2-4-tBu-6-R-C6H2O)2]TiCl2 [R = CMe3 (1)、CMe2Ph (2)、CMePh2 (3)、CPh3 (4)和 C(p-Tol)3 (5)]通过在甲苯中直接用 HCl 消除 TiCl4 与相应配体前体的反应以高产率合成。离子钛配合物[NHEt3][S(2-CH2-4-tBu-6-R-C6H2O)2TiCl3] [R = CMe3 (6)、CMePh2 (7)]和[NH2Et2][S(2-CH2-4-tBu-6-R-C6H2O)2TiCl3] [R = CMe3 (8)和 CMePh2 (9)]通过在相应配体前体存在下与 TiCl4 反应以高产率获得，存在 2 eq 的三乙胺或二乙胺。中性锆配合物[S(2-CH2-4-tBu-6-R-C6H2O)2]ZrCl2(THF) [R = CMe2Ph (10·THF)和 CMePh2 (11·THF)]通过 ZrCl4 与相应配体前体 Li2L 的 1 eq 二锂盐在 THF 中的反应合成。新的钛和锆配合物通过 1H 和 13C NMR、IR 和元素分析进行了表征。配合物 4、6 和 10·THF 的分子结构通过单晶 X 射线衍射分析确定。X 射线晶体学分析表明，钛配合物 4 具有围绕中心金属原子的五配位环境，而钛配合物 6 和 THF 溶剂化的锆配合物 10·THF 具有围绕中心金属原子的六配位拟八面体环境。用 MAO 或 AliBu3/Ph3CB(C6F5)4 活化后，所有这些钛和锆配合物在乙烯聚合和乙烯/1-己烯共聚中表现出中等至高的催化活性，具有中等至高的共聚单体掺入，并且在类似条件下，离子钛配合物 6、7、8 和 9 的催化活性低于它们相应的中性配合物。
