posted on 2020-04-29, 19:16authored byYang Wang, Chulu Zhou, Jianhua Cheng
The binuclear half-sandwich
scandium aminobenzyl/chloride complex [(Cp′)Sc(THF)Cl]2[p-(CH2C6H3(o-NMe2)−)2] (Cp′
= C5Me4SiMe3) (2) was
synthesized by linking two scandium centers through a bis(aminobenzyl)
fragment. When activated with a halide abstractor, [(Et3Si)2(μ-H)][B(C6F5)4], complex 2 is capable of copolymerizing styrene and
ε-caprolactone to furnish ABA-type triblock copolymers
(PCL-b-sPS-b-PCL)
consisting of perfectly syndiospecific polystyrene (sPS) (B) in the midblock and tunable PCL (A) content in the end blocks. The stress–strain measurements
of a solution casting film of copolymers demonstrated that the triblock
copolymers exhibited superior mechanical performances compared to
those diblock BA copolymers (sPS-b-PCL) prepared from mononuclear scandium aminobenzyl/chloride
complex [(Cp′)Sc(o-CH2C6H4–NMe2)(THF)Cl](1).