Reduction of fully substituted titanocene dichlorides [TiCl2(η5-C5Me4R)2] (R= SiMe2CH2CH2Ph,3; SiMe2Ph,4; and SiMePh2, 5) with magnesium in THF proceeds via the formation of titanocene monochlorides. Titanocene monochlorides give the expected EPR spectra in toluene solution and glass.
The structure of 7 was further corroborated by single-crystal X-ray diffraction. Titanocenes 9-11 are EPR silent down to -196.DEG.C but exhibit paramagnetic broadening of the signals in solution NMR spectra.
The positions of the NMR signals are temperature-dependent, obeying the Curie Law in the range investigated (0-60.DEG.C).