Lipophilic halogenozirconocene(<scp>III</scp>) complexes: [{Zr[η-C₅H₃(SiMe₃)₂-1,3]₂(µ-Cl)}₂], [NBuⁿ₄][Zr{η-C₅H₃(SiMe₃)₂-1,3}₂Cl₂] and [Zr{η-C₅H₃(SiMe₃)₂-1,3}₂Cl₂]

Abstract

Treatment of [Zr{η-C5H3(SiMe3)2-1,3}2X2] with Na–Hg in tetrahydrofuran (THF) affords the blue (X = Cl 2a or Br) or green (X = I) crystalline complexes [{Zr[η-C5H3(SiMe3)2-1,3]2(µ-X)}2], with characteristic ZrIII ESR spectra (PhMe, 300 K) and exceptionally long (3.86–4.17 Å) Zr ⋯ Zr contacts; 2a is susceptible to facile Zr(µ-Cl)2Zr bridge-cleavage upon reaction with either a neutral (e.g. THF) or an anionic (e.g. Cl–) nucleophile, as in its conversion into [NBun4][Zr{η-C5H3(SiMe3)2-1,3}2Cl2].