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A phenoxy-imine proligand with the additional OH donor group, 4,6-tBu2-2-(2-CH2(OH)-C6H4N = CH)C6H3OH (LH2), was synthesized and used to prepare group 4 and 5 complexes by reacting with Ti(OiPr)4 (LTi) and VO(OiPr)3 (LV). All new compounds were characterized by the FTIR, 1H and 13C NMR spectroscopy and LTi by the single-crystal X-ray diffraction analysis. The complexes were used as catalysts in the ring opening polymerization of ε-caprolactone. The influence of monomer/transition metal molar ratio, reaction time, polymerization temperature as well as complex type was investigated in detail. The complexes showed high (LTi) and moderate (LV) activity in ε-caprolactone polymerization and the resultant polycaprolactones exhibited Mn and Mw/Mn values ranging from 4.0 · 103 to 18.7 · 103 g/mol and from 1.4 to 2.5, respectively.

This paper gives a short overview of homogeneous post-metallocene catalysts based on group 4 metal and vanadium complexes bearing multidentate ligands. It summarizes the catalytic behavior of those catalysts in copolymerization of ethylene with 1-olefins, with styrenic monomers and with α,ω-alkenols. The review is focused on finding correlations between the structure of a complex, its catalyst activity and comonomer incorporation ability, as well as the microstructure of the copolymer chains.

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Novel vanadium complexes bearing [OSSO]-type ligands having two phenolato units linked through the -CH 2 S(CH 2 ) 4 SCH 2 -(1V) or -CH 2 S(CH 2 ) 2-SCH 2 -(2V) bridge are synthesized with good yields by reacting a deprotonated ligand with VCl 4 . They are then used in ethylene (co)polymerization after activation with EtAlCl 2 and Et 2 AlCl. In the presence of EtAlCl 2 , both complexes promote ethylene polymerization with very high activities, over 4 9 10 7 g/(mol h), leading to PEs with high molecular weight and narrow molecular weight distribution. The prepared complexes exhibit lower activity for ethylene/1-octene copolymerization. It is also revealed that the catalyst based on the -CH 2 S(CH 2 ) 4 SCH 2 -bridged complex shows both higher activity and higher comonomer incorporation ability than the catalyst based on the -CH 2 S(CH 2 ) 2 SCH 2 -bridged complex. Upon activation with Al(iBu) 3 /Ph 3 CB(C 6 F 5 ) 4 , complex 2V produces stereo-and regioirregular poly(1-octene), while 1V gives the isotactically enriched product.

Homopolymerization of styrenic monomers (St, p‐Me‐St, p‐tBu‐St, p‐tBuO‐St) and their copolymerization with ethylene, with the use of [(tBu2O2NN′)ZrCl]2(μ‐O) (1) and (tBu2O2NN′)TiCl2 (2), where tBu2O2NN′ = Me2N(CH2)2N(CH2‐2‐O−‐3,5‐tBu2‐C6H2)2, is explored in the presence of MMAO and (iBu)3Al/Ph3CB(C6F5)4. The ethylene/styrenic monomers copolymerization with 1/MMAO produces exclusively copolymers with high activity and good comonomer incorporation whereas the other catalytic systems yield mixtures of copolymers and homopolymers. The use of p‐alkyl styrene derivatives instead of styrene raises the catalytic activity, comonomer incorporation and molecular weights of the copolymers. Complex 2 exhibits higher activity in homopolymerization of styrenic monomers than 1 irrespective of the kind of the activator employed. A clear dependence is observed for the molecular weight and catalyst activity against the kind of the styrenic monomer. The obtained polymers were atactic and only the complex 2, when activated by MMAO, promoted the highly syndiospecific polymerization of p‐Me‐St and p‐tBu‐St. Poly(p‐tBuO‐St) exhibits fiber‐forming properties.

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