Iron and Cobalt Complexes of 4‐Alkyl‐2,6‐diiminopyridine Ligands: Synthesis and Ethylene Polymerization Catalysis

Abstract

A new methodology for selective alkylation of the 2,6-diiminopyridine (pdi) ligands allows the ready synthesis of new derivatives displaying 2-methyl-2-phenylpropyl (neophyl), benzyl, or allyl groups in the 4-position of the pyridine ring. A set of Fe and Co complexes containing the new ligands have been synthesized and fully characterized. The presence

Carbocyclic-fused N,N,N-pincer ligands as ring-strain adjustable supports for iron and cobalt catalysts in ethylene oligo-/polymerization

“…The role played by substituents on the 4-position of the central pyridine ring on the catalytic performance of bis(arylimino)pyridine-iron and -cobalt complexes 10 [65] ( Figure 10) has been studied by the Cámpora group. While the introduction of 4-alkyl groups generally increases the solubility of the complexes, the impact on the catalytic activity was rather limited.…”

Bi- and tri-dentate imino-based iron and cobalt pre-catalysts for ethylene oligo-/polymerization

“…The Cámpora group have investigated whether the presence of 15 4-neophyl, 4-benzyl or 4-allyl groups would affect the ethylene polymerization properties of the complexes 115-120 (Scheme 18). 61 The impact of an alkyl substituent on the catalytic properties of the 4-neophyl and 4-benzyl derivatives was negligible, and basically only served to increase the 20 solubility of the system. This suggests that the methodology could well be advantageous for the introduction of groups suitable for immobilization; other methods tend to have the linker functionality placed in a position where it may have a significant influence on the catalyst activity.…”

Iron(III) complex of a tridentate NNN type ligand: synthesis, X-ray structure, thermal analysis and voltammetric studies

“…After the synthesis of tridentate bis(N-pyrazolyl) pyridyl ligands by Jameson and Goldsby, there has been growing interest in using this ligand instead of terpyridine due to its easy synthesis and modification [2]. The coordination chemistry of iron complexes with NNN-type donor ligands has been discussed with respect to their spin-state behaviour, capabilities to serve as catalysts of organic reactions [3], and importance as synthetic models for the iron-containing enzymes [4]. Also, Hayami and co-workers [5] synthesized material exhibiting metallomesogenic properties for a low-spin iron(II) complex with a terpy analogue.…”