The copolymerization of ethylene and 5-hexen-1-ol (M2) masked by 1.1 equivalents of AliBu3 is carried out by four rare-earth metal catalysts bearing different steric hindrances: (Flu-CH2-Ph)Sc(CH2SiMe3)2(THF) (1)，(Flu-CH2-C5H4N)Sc(CH2SiMe3)2 (2)

(Flu-CH2CH2-NHC-C6H2Me3-2

4

6)Sc(CH2SiMe3)2 (3)

(Flu-CH2CH2-NHC-C6H4Me)Sc(CH2SiMe3)2 (4). Among them

complex 1 shows the highest catalytic activity (1.32×106 g·molSc−1·h−1) but gives pure polyethylene without detectable M2 unit

and

in contrast

complex 2 is nearly inert. Under same conditions

the bulkier complex 3 shows moderate activity (0.38×106 g·molSc−1·h−1) and low comonomer incorporation (0.7 mol%). On switching to the bulkiest complex 4

the copolymerization process is obviously promoted with a catalytic activity of 1.24×106 g·molSc−1·h−1 and generates a copolymer with 1.8 mol% M2. For the polar vinyl monomers having different CH2 spacers between polar and vinyl groups

complex 4 exhibits the best catalytic performance for the copolymerization of ethylene with 10-undecene-1-ol with the highest catalytic activity (11.91×106 g·molSc−1·h−1) and the strongest incorporation ability (4.9 mol%). The influence of reaction conditions such as comonomer concentration

polymerization temperature and ethylene pressures on the catalytic performance of complex 4 are screened. The microstructures and thermal properties of the resultant copolymers are well-characterized by NMR

GPC and DSC.