Zirconocene compounds derived from boratastilbene, 4-boratastyrylstilbene, and 1,4-bis(boratastyryl)benzene and their reactivities to the ethylene polymerization

Abstract

(η 6-Boratastilbene)(η 5-pentamethylcyclopentadienyl)zirconium dichloride ( 1), (η 6-4-boratastyrylstilbene)(η 5-pentamethylcyclopentadienyl)zirconium dichloride ( 2), [1,4-bis(boratastyryl)benzene]bis[(dichloro)(pentamethylcyclopentadienyl)zirconium] ( 3), and bis(η 6-boratastilbene)zirconium dichloride ( 4) were synthesized. The crystal structure of 1 was determined by X-ray crystallography. These zirconium complexes show activities in the presence of methylaluminoxane (MAO) for the polymerization of ethylene. The activities are in the following order: 1> 2>Cp 2ZrCl 2> 3> 4. The activity of 1 is three times higher than that of Cp 2ZrCl 2 under similar conditions.