Highly Active and Isospecific Styrene Polymerization Catalyzed by Zirconium Complexes Bearing Aryl-substituted [OSSO]-Type Bis(phenolate) Ligands

Norio Nakata; Tomoyuki Toda; Yusuke Saito; Takanori Watanabe; Akihiko Ishii

doi:10.3390/polym8020031

Highly Active and Isospecific Styrene Polymerization Catalyzed by Zirconium Complexes Bearing Aryl-substituted [OSSO]-Type Bis(phenolate) Ligands

Polymers (Basel). 2016 Jan 26;8(2):31. doi: 10.3390/polym8020031.

Authors

Norio Nakata¹, Tomoyuki Toda², Yusuke Saito³, Takanori Watanabe⁴, Akihiko Ishii⁵

Affiliations

¹ Department of Chemistry, Graduate School of Science and Engineering, Saitama University, 255 Shimo-okubo, Sakura-ku, Saitama 338-8570, Japan. nakata@chem.saitama-u.ac.jp.
² Department of Chemistry, Graduate School of Science and Engineering, Saitama University, 255 Shimo-okubo, Sakura-ku, Saitama 338-8570, Japan. t.toda@mst.nagaokaut.ac.jp.
³ Department of Chemistry, Graduate School of Science and Engineering, Saitama University, 255 Shimo-okubo, Sakura-ku, Saitama 338-8570, Japan. s13ds003@mail.saitama-u.ac.jp.
⁴ Department of Chemistry, Graduate School of Science and Engineering, Saitama University, 255 Shimo-okubo, Sakura-ku, Saitama 338-8570, Japan. s14mc129@mail.saitama-u.ac.jp.
⁵ Department of Chemistry, Graduate School of Science and Engineering, Saitama University, 255 Shimo-okubo, Sakura-ku, Saitama 338-8570, Japan. ishiiaki@chem.saitama-u.ac.jp.

Abstract

[OSSO]-type dibenzyl zirconium(IV) complexes 9 and 10 possessing aryl substituents ortho to the phenoxide moieties (ortho substituents, phenyl and 2,6-dimethylphenyl (Dmp)) were synthesized and characterized. Upon activation with dMAO (dried methylaluminoxane), complex 9 was found to promote highly isospecific styrene polymerizations ([mm] = 97.5%⁻99%) with high molecular weights M_w up to 181,000 g·mmol^-1. When the Dmp-substituted pre-catalyst 10/dMAO system was used, the highest activity, over 7700 g·mmol(10)^-1·h^-1, was recorded involving the formation of precisely isospecific polystyrenes of [mm] more than 99%.

Keywords: [OSSO]-type ligand; isotactic; post-metallocene; styrene polymerization; zirconium.