Preparation and crystal-structures of low-valent zirconocene complexes containing tetramethyl(phenyl)cyclopentadienyl ligand

Abstract

Zirconocene complex [ZrCl2(η5-C5Me4Ph)2] (1) prepared by metathesis of the appropriate lithium cyclopentadienide and ZrCl4 was reduced with magnesium in tetrahydrofuran in the presence of excess bis(trimethylsilyl)acetylene, yielding the low-valent complex [Zr(η5-C5Me4Ph)2(η2-Me3SiC=CSiMe3)] (2). However, in addition to 2, the reduction afforded an unexpected Zr(II) complex [Zr(η5-C5Me4Ph)2(s-trans-η4-buta-1,3-diene)] (3).

Compounds 1-3 were characterized by spectroscopic methods and by X-ray single-crystal diffraction.

Keywords

• metallocenes
• zirconocenes
• bis(trimethylsilyl(acetylene)
• low-valent complexes
• alkynes
• crystal structure
• X-ray diffraction
• cyclopentadienyl ligands