Pyridylamido Bi-Hafnium Olefin Polymerization Catalysis: Conformationally Supported Hf···Hf Enchainment Cooperativity
作者:Yanshan Gao、Aidan R. Mouat、Alessandro Motta、Alceo Macchioni、Cristiano Zuccaccia、Massimiliano Delferro、Tobin J. Marks
DOI:10.1021/acscatal.5b00788
日期:2015.9.4
Homobimetallic Hf(IV) complexes, L2-Hf2Me5 (3) and L2-Hf2Me4 (4) (L2 = N,N′-[naphthalene-1,4-diylbis(pyridine-6,2-diyl)]bis[(2-isopropylphenyl)methylene)]bis(2,6-diisopropylaniline}), were synthesized by reaction of the free ligand L2 with the appropriate Hf precursor and were characterized in solution (NMR) and in the solid state (X-ray diffraction). In 3, L2 acts as a dianionic tridentate ligand for one Hf
同金属Hf(IV)配合物L 2 -Hf 2 Me 5(3)和L 2 -Hf 2 Me 4(4)(L 2 = N,N '-[萘-1,4-二基双吡啶(吡啶-6)通过游离配体L 2与合适的Hf前体的反应合成1,2,2-二基]]双[((2-异丙基苯基)亚甲基)]双(2,6-二异丙基苯胺}),并在溶液中进行表征(NMR)和在固态(X射线衍射)。在3,L 2充当一个Hf金属中心的双阴离子三齿配体,并充当另一个Hf金属中心的单阴离子双齿配体,而在4中,两个Hf单元三配位于L 2的相对侧。在固态状态下,Hf···Hf距离在3 vs 4(分别为6.16 vs 8.06Å)中有显着差异,但是在溶液中,双活化复合物3中两个连接的金属单元的结构动力学接近构象异构体。 Hf···Hf距离更近(约3.2Å)。用Ph 3 C + B(C 6 F 5)4 –(B 1)或PhNMe 2 H激活后+ B(C 6 F 5)4