New half-sandwich zirconium(IV) complexes containing salicylaldimine ligands: Synthesis, characterizations and catalytic properties

Abstract

Two new half-sandwich zirconium(IV) complexes bearing salicylaldimine ligands of the type Cp*Zr[2-t Bu-4-R-6-(CH=N i Pr)C 6 H 2 O]Cl 2 [R=H(1), t Bu(2)] were prepared by the reaction of Cp*ZrCl 3 with the corresponding lithium of salicylaldimine ligands 2-t Bu-4-R-6-(CH=N i Pr)C 6 H 2 OLi[R=H(LiLa), t Bu(LiLb)]. Complexes 1 and 2 were characterized by 1 H NMR, 13 C NMR spectroscopy and elemental analysis. When activated with Al i Bu 3 and Ph 3 CB(C 6 F 5 ) 4 , both complexes 1 and 2 exhibited reasonable catalytic activities for ethylene polymerization, producing polyethylenes with moderate molecular weight. Complexes 1 and 2 also exhibited reasonable catalytic activities for ethylene copolymerization with 1-hexene, producing poly(ethylene-co-1-hexene)s with moderate molecular weight and reasonable 1-hexene content.

Research Progress of Pre - transition Metal Olefin Polymerization Catalyst for Salicylaldehyde Imine

“…Fig.4 By analyzing the structure of the transition metal catalyst and the metallocene catalyst of salicylaldehyde imide, it is found that the zeolite of the bis-salicylaldehyde imide Ti has a octahedral structure, similar to the tetrahedral structure of the zirconocene and zirconocene catalyst and the catalyst with these structures has good polymerization properties. Huang et al [21] synthesized a series of monocarbamate Schiff base mixed ligand Zr complex (catalyst 29 ~ 31). The eff ects of substituents on cyclopentadiene on the copolymerization of ethylene / 1-hexene were investigated.…”

Research progress of pre-transition metal olefin polymerization catalyst for salicylaldehyde imine

“…The steric hindrance of catalyst 31 was the largest, but the catalyst activity was the highest, achieving 1.2 × 106 g of copolymer/(mol Zrh. In 2014, Liu et al [22] synthesized two novel monocarbophore Schi-base mixed ligand Zr complexes 32 and 33, and the phenoxy groups were Bu substituents to catalyze the ethylene/1-hexene copolymerization. The relative molecular mass of the activity and the polymerization product is higher than that of the unsubstituted catalyst, which is due to the electron effect of the t Bu substituent, which stabilizes the cationic active center of the catalyst and increases the catalytic activity.…”