Nickel(II) complexes bearing the bis(β‐ketoamino) ligand for the copolymerization of norbornene with a higher 1‐alkene

Abstract

A novel bis(b-ketoamino)Ni(II) complex catalyst, Ni{CF 3 C(O)CHC[N(naphthyl)]CH 3 } 2 , was synthesized, and the structure was solved by a single-crystal X-ray refraction technique. The copolymerization of norbornene with higher 1-alkene was carried out in toluene with catalytic systems based on nickel(II) complexes, Ni{RC(O)CHC[N(naphthyl)]CH 3 } 2 (R¼ ¼CH 3 , CF 3 ) and B(C 6 F 5 ) 3 , and high activity was exhibited by both catalytic systems. The effects of the catalyst structure and comonomer feed content on the polymerization activity and the incorporation rates were investigated. The reactivity ratios were determined to be r 1-octene ¼ 0.009 and r norbornene ¼ 13.461 by the Kelen-Tü dõs method for the Ni{CH 3 C(O)CHC[N(naphthyl)]CH 3 } 2 /B(C 6 F 5 ) 3 system. The achieved copolymers were confirmed to be vinyl-addition copolymers through the analysis of 1 H-NMR and 13 C-NMR. The thermogravimetric analysis results showed that the copolymers exhibited good thermal stability (decomposition temperature, T dec > 400 C), and the glass-transition temperature of the copolymers were observed between 215 and 275 C. The copolymers were confirmed to be noncrystalline by wide-angle X-ray diffraction analysis and showed good solubility in common organic solvents.

Copolymerization of Norbornene and Styrene with Anilinonaphthoquinone-Ligated Nickel Complexes

“…The properties of COCs can be easily controlled by a kind of comonomer, comonomer content, and sequence distribution. Copolymerization of N with 1-alkene was also reported to modify the physical properties [16,17,18,19,20,21,22,23,24]. The introduction of styrene (S) should decrease the birefringence of COCs [25] because PNB and polystyrene possess positive and negative birefringence, respectively.…”

Synthesis and Properties of Gradient Copolymers Composed of Norbornene and Higher α-Olefins Using an ansa-Fluorenylamidodimethyltitanium-[Ph3C][B(C6F5)4] Catalyst System

“…Great efforts have also been devoted to the design of catalysts for the copolymerization of NB and higher α-olefins. In addition to early-transition-metal complexes, such as methylene-bridged ansa -zirconocenes and half-titanocenes, late-transition-metal complexes − have also been found to show activity for NB/α-olefin copolymerization. However, when these complexes are applied, the yield of the NB/α-olefin copolymer usually decreases with increasing amount of α-olefin in the feed.…”

Highly symmetric single nickel catalysts bearing bulky bis(α-diimine) ligand: Synthesis, characterization, and electron-effects on copolymerization of norbornene with 1-alkene at elevated temperarure

“…For example, they are normally brittle at room temperature and have poor solubility in common organic solvents. So, the properties of cyclic olefin copolymer should be improved by the comonomer employed, especially copolymerization of norbornene with 1‐alkene . Since Brookhart and coworkers reported an unique class of single metal center α‐diimine catalysts that having excellent properties in olefin polymerization, a series of α‐diimine Ni and Pd complexes with different N ‐aryl moiety substitutions and ligand backbone modifications have been successfully developed.…”