| 摘要 |
Addition polymerization catalysts of the formula L ~ MX+ A- prepared by oxidation of a Group 4 or Lanthanide metal derivative of the formula L~ MX2 with an oxidizing agent of the formula (Ox +a)b(A-)d are free of interfering amine or phosphine byproducts. In these formulae:- L independently each occurrence is a ligand or ligand system, especially a n5-cyclopentadienyl group optionally covalently bonded to M throng a substituent; ~ is an integer, especially 1; M is a Group 24 or the Lanthanide metal, especially titanium or zirconium; X is hydride or a hydrocarbyl, silyl or germyl group having up to 20 carbon, silicon or germanium atoms, especially benzyl; A- is a monovalent, compatible, noncoordinating anion, especially perfluorotetraphenyl borate; Ox +a is a cationic oxidizer having a charge of (+a), especially Ag+ or ferrocenium; and b and d are integers selected to provide charge balance.
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