Synthesis, characterization, and styrene polymerization performance of organo yttrium complexes supported by imino-fuctionalized indenyl ligand

ABSTRACT

Amine elimination of Y[N(SiHMe₂)₂]₃(THF)₂ with the imino-functionalized indenyl ligand C₉H₇CH₂CH = N-2,6-ⁱPr₂C₆H₃ in 1:1 and 1:2 molar ratio afforded the mono-indenyl-ligated yttrium bis(silylamide) complex (C₉H₆CH₂CH = N-2,6-ⁱPr₂C₆H₃)Y[N(SiHMe₂)₂]₂ (4) and the neutral yttrium complex (C₉H₆CH₂CH = N-2,6-ⁱPr₂C₆H₃)(C₉H₆CH = CH-N-2,6-ⁱPr₂C₆H₃)Y (5), respectively. Both complexes were characterized by elemental analysis and NMR. X-ray single crystal structural diffraction showed that the central metal in 5 is four-coordinated by two indenyl ligands and two nitrogen atoms in η⁵/κ¹-mode, if the indenyl ring is regarded as occupying an independent vertex. In the presence of AlⁱBu₃ and activated by one equimolar amount of [Ph₃C][B(C₆F₅)₄], complex 4 showed activity toward syndiospecific polymerization of styrene.

KEYWORDS:

• Yttrium amide complex
• indenyl ligand
• styrene
• syndiospecific polymerization

Acknowledgments

The authors are grateful to Mr. Zhang Yong at Suzhou University for X-ray single crystal analysis.

Funding

This project was supported by the National Natural Science Foundation of China (21572205) and Zhejiang Provincial Natural Science Foundation (LY15B020006).