| 摘要 |
<p>Metal imido complexes of Group V or VI metals suitable for use as olefin polymerisation catalysts have the general formula I or II. <CHEM> <CHEM> wherein in Formula I M is Group V metal and in Formula II M is Group VI metal. R = alkyl or aryl and may be the same or different, Z = bridging group chosen from (CH2)x wherein x = 3-6, arylalkylene, or heteroalkylene groups, X = organic group containing a cyclopentadienyl nucleus, Y = univalent anionic ligand, halide, amido, hydrogen, alkyl or aryl and may be the same or different, and with the proviso that when M is niobium or tungsten R is not aryl. Particularly preferred complexes are those in which the metal is chromium or vanadium. The catalysts show an improved resistance to poisons.</p> |
