Mono salicylaldiminato vanadium(III) complexes (

1a-1f

) [RN = CH(ArO)]VCl

2

(THF)

2

(Ar = C

6

H

4

(

1a-1e

)

R = Ph

1a

; R =

p

-CF

3

Ph

1b

; R = 2

6-Me

2

Ph

1c

; R = 2

6-iPr2Ph

1d

; R = cyclohexyl

1e

; Ar = C

6

H

2

t

Bu

2

(2

4)

R = 2

6-

i

Pr

2

Ph

1f

) and bis(salicylaldiminato) vanadium(III) complexes (

2a-2f

) [RN = CH(ArO)]

2

VCl(THF)

x

(Ar = C

6

H

4

(

2a-2e

)

x

= 1 (

2a-2e

)

R = Ph

2a

; R =

p

-CF

3

Ph

2b

; R = 2

6-Me

2

Ph

2c

; R = 2

6-

i

Pr

2

Ph

2d

; R = cyclohexyl

2e

; Ar = C

6

H

2

t

Bu

2

(2

4)

R = 2

6-

i

Pr

2

Ph

x

= 0

2

f

) have been evaluated as the active catalysts for ethylene/1-hexene copolymerization in the presence of Et

2

AlCl. The ligand substitution pattern and the catalyst structure model significantly influenced the polymerization behaviors such as the catalytic activity

the molecular weight and molecular weight distribution of the copolymers

etc

. The highest catalytic activity of 8.82 kg PE/(mmol

V

×h) was observed for vanadium catalyst

2d

with two 2

6-diisopropylphenyl substituted salicylaldiminato ligands. The copolymer with the highest molecular weight was obtained by using mono salicylaldiminato vanadium catalyst

1f

having ligands with

tert

-butyl at the

ortho

and

para

of the aryloxy moiety.