Reactions of HfCl4 with 2 and 3 equiv. of Li[C4H 3N(CH2NMe2)-2] in toluene afford HfCl 2[C4H3N(CH2NMe2)-2] 2 (1) and HfCl[C4H3N(CH2NMe 2)-2]3 (2), respectively. Transmetallation reaction of 1 with 2 equiv. of MeLi results in a hafnium dimethyl compound HfMe 2[C4H3N(CH2NMe2)-2] 2 (3). A variable-temperature 1H NMR spectroscopic study shows that the activation energy for the dissociation/association of the NMe2 units of compound 2 in solution is ca. 13.6 kcal/mol. Compounds 1-3 are characterized by NMR spectroscopy and single crystal X-ray diffraction. A polymerization study shows that compounds 1 and 3 exhibit moderate activity toward ethylene in the presence of TIBA and MAO.
All Science Journal Classification (ASJC) codes
- Physical and Theoretical Chemistry
- Inorganic Chemistry
- Materials Chemistry