Metallocene halides. Part I. Synthesis, spectra, and redistribution equilibria of di-π-cyclopentadienyldihalogeno-titanium(IV),-zirconium-(IV), and -hafnium(IV)

Abstract

An improved synthesis of (π-C₅H₅)₂HfCl₂ and new method for preparing Group IVA metallocene fluorides, bromides, and iodides from either boron halides or C₆F₅CN, are reported. Vibrational (4000–600 cm.^–1), ¹H n.m.r., and mass spectra are presented. The mixed halides (π-C₅H₅)₂MClBr have been identified by n.m.r. spectroscopy; in tetrahydrofuran solutions, redistribution equilibria (π-C₅H₅)₂MCl₂+(π-C₅H₅)₂MBr₂⇌ 2(π-C₅H₅)₂MClBr at 38° are approximately statistical.