Coordination Polymerization of Renewable (E)-4,8-Dimethyl- 1,3,7-Nonatriene by Rare-Earth Metal Catalysts
作者：ang Jiang, Zhen Zhang, Shihui Li* and Dongmei Cui
關鍵字：Biobased monomer | Ligand effects | Homogeneous catalysis | Polymerization | Elastomer
論文來源：期刊
發表時間：2022年
Coordination polymerization of renewable (E)-4,8-dimethyl-1,3,7-nonatriene (DMNT) has been performed using pyridyl-methylene-fluorenyl scandium complex 1, half-sandwich scandium complex 2, diiminophosphinato rare-earth metal complexes 3a—3c and 4a—4b, bis(phosphino)carbazolide yttrium complex 5 and β-diketiminato yttrium complex 6. Fluorenyl scandium complexes 1 and 2, activated by [Ph3C][B(C6F5)4] and AliBu3, are moderately active and show perfect 1,2-regioselective (1,2 >99%). Conversely, asymmetric diiminophophinato complexes 3a—3c promote the DMNT polymerization to produce high trans-1,4 regulated products with the activity trend: Sc < Lu < Y. Complexes 4—6 are virtually inactive for the DMNT polymerization although they are highly active in isoprene polymerization. A diblock copolymer bearing 3,4-polyisoprene block and trans-1,4-poly (DMNT) block is obtained using complex 3c in one-pot reaction. Hydrogenation of trans-1,4-poly (DMNT) affords an elastomer with a Tg of ?10 oC. The epoxidation reaction of trans-1,4-poly (DMNT) with 3-chloroperbenzoic acid transfers the pendant double bonds in the cis configuration into the epoxy groups.
