Zr and Hf metallocenes. Study of the structure of a novel mononuclear zirconium trivalent organometallic

Abstract

Cp 2 ∗MCl 2, M  Zr and Hf, were obtained by reaction of MCl 4 with Cp ∗Li, where Cp ∗  1,3-di-tertbutylcyclopentadienyl. Reduction of Cp 2 ∗MCl 2 with metallic potassium in pentane gave Cp 2 ∗MCl. The molecular and crystal structure of Cp 2 ∗ZrCl was established from X-ray diffraction; monoclinic, space group P2 1/ b , a  12.722, b  16.336, c  13.426 Å, γ  70.68°, R  0.065; monomeric Cp 2 ∗ZrCl molecules, the average ZrC bond length is 2.505 Å, that of ZrCl is 2.423 Å, and the Cp ∗centroidZrCp ∗centroid angle is 133.3°.