Synthesis of neutral nickel catalysts for ethylene polymerization ? the influence of ligand size on catalyst stabilityElectronic supplementary information (ESI) available: experimental protocol for (tmeda)Ni(Me)2 and compounds 3,4,7,8,9 and 10 and 1H-NMR magnetization transfer data for compound 7. See http://www.rsc.org/suppdata/cc/b3/b306701g/

Abstract

A facile synthesis of nickel salicylaldimine complexes with labile dissociating ligands is described. In addition to producing highly active ethylene polymerization catalysts, important insights into the effect of ligand size on catalyst stability and information on the mechanism of polymerization are provided.

Bimetallic nickel complexes of macrocyclic tetraiminodiphenols and their ethylene polymerization

“…They may not require cocatalysts such as methylaluminoxane (MAO) or borate and they are compatible with polar groups enabling incorporation of polar monomers. When 1-5 are reacted with (tmeda)NiMe 2 in order to prepare phosphine free nickel complexes, [9] broad signals are observed in the 1 H NMR spectra, which are not clearly assignable. Treatment of KH in THF affords cleanly the dipotassium salts.…”

Novel nickel(II) and copper(II) complexes with phenoxy-imidazole ligands: Syntheses, crystal structures and norbornene addition polymerization

“…It is noticeable that the coordinate geometry of the metal Ni(II) obviously deviates from the preferred square planar struc- ture and takes distorted tetrahedral coordination geometry because of the steric hindrance of the butyl of phenol and a phenyl group of imidazole ring. [13] The Ni(1)-O and Ni(1)-N distances are 1.884(3) and 1.971(2) Å , respectively, which are longer than those (1.828 (6) and 1.908(7) Å , respectively) found in the bis[(N-2,6-diisopropylphenyl)salicylaldiminate]nickel(II) complex [14]. The lengths of Cu(1)-O and Cu(1)-N (1.891(2) and 1.945(2) Å , respectively) are similar to those of bis(salicylaldiminate)copper(II) complex [15].…”

Supported Single-Site Organometallic Catalysts for the Synthesis of High-Performance Polyolefins

“…5) [36][37][38][39][40][41][42] and Grubbs and co-workers (Group 10, Fig. 5) [43][44][45][46]. In 1995, Brookhart and coworkers reported high activity a-diimine Ni and Pd complexes which are able to co-polymerize ethylene with polar monomers (Fig.…”