The Magnetic Properties of the Cyclopentadienyltitanium(III) Derivatives CpTiCl2, Cp2TiCl, and Cp3Ti

The synthesis of tris(cyclopentadienyl)titanium(III) in high yield is presented. The effect on the magnetic properties of titanium trichloride of introducing successively one, two, and three cyclopentadienyl ligands is examined. CpTiC12 behaves as a magnetically dilute compound whose susceptibility follows a Curie-Weiss law, and the susceptibility (mu eff = 1.69 +/- 0.05 B.M.) indicates little if any spin-spin interaction. With two cyclopentadienyl groups present (cp2TiCl), spin-spin interaction through chlorine bridges becomes evident. The susceptibility of Cp3Ti was determined between 100 and 320 K and was found to be independent of temperature over this range. After correcting for T.I.P. and applying a Weiss constant, mu eff was found to be 1.71 B.M. The volatility and solubility of Cp3Ti are strong indications of its monomeric nature. Infrared and electronic spectra of the solid cyclopentadienyl species and titanium trichloride were measured over the range 250-30,000 cm-1