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

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.