Abstract:

The characterization of a series of carbonyl adducts of open titanocenes, open vanadocenes and half-open vanadocene was studied with IR, EPR and UV-VIS methods. The electronic structures of [2,4-(CH_3)_2C_5H_5]_2VCO, [2,4-(CH_3)_2C_5H_5]_2TiCO and [2,4-(CH_3)_2C_5H_5](C_5H_5)VCO have been calculated by EHMO mehtod. The compar ison between carbonyl adducts of open vanadocene, half-open vanadoce and vanadocene has been carried out and the results show that the properties of half-open vanadoce lie between open vanadoce and vanadocene, and tend to open vanadocene. The bond of vanaium-pentadienyl is stronger than that of vanadium-cyclopentadienyl. The properties of half-open vanadocene are more affected by the pentadienyl ligand than by the cyclopentadienyl ligand.

Key words: Open metallocene, Pentadienyl