Nitro-substituted iron(II) tridentate bis(imino)pyridine complexes as high-temperature catalysts for the production of α-olefins

Autor: Douglas J. Adelman, William J. Marshall, Rupert Spence, Aaron Lewis Shoe, Alex Sergey Ionkin, Tuyu Xie
Rok vydání: 2006
Předmět:
Zdroj: Journal of Polymer Science Part A: Polymer Chemistry. 44:2615-2635
ISSN: 1099-0518
0887-624X
DOI: 10.1002/pola.21360
Popis: A new series of nitro-substituted bis(imino)pyridine ligands {2,6-bis[1-(2-methyl-4-nitrophenylimino)ethyl]pyridine, 2,6-bis[1-(4-nitrophenylimino)ethyl]pyridine, (1-{6-[1-(4-nitro-phenylimino)-ethyl]-pyridin-2-yl)-ethylidene)-(2,4,6-trimethyl-phenyl)-amine, and 2,6-bis[1-(2-methyl-3-nitrophenylimino)ethyl]pyridine) and their corresponding Fe(II) complexes [{p-NO 2 -o-Me-Ph-N=C(Me)-Py-C(Me)=N-Ph-o-Me-p-NO 2 }FeCl 2 (10), L 2 FeCl 2 (11), {m-N02-o-Me-Ph-N=C(Me)-Py-C(Me)-N-Ph-o-Me-m-NP 2 }FeCl 2 (12), and {p-N02-Ph-N=C(Me)-Py-C(Me)=N-Mes} FeCl 2 (14)] were synthesized. According to X-ray analysis, there were shortenings of the axial Fe-N bond lengths (up to 0.014 A) in para-nitro-substituted complex 10 and (up to 0.015 A) in meta-nitro-substituted complex 12 versus the Fe(II) complex without nitro groups [{o-Me-Ph-N-C(Me)-Py-C(Me)=N-Ph-o-Me)FeCl2 (1)]. Complexes 10, 12, and 14 afforded very active catalysts for the production of α-olefins and were more temperature-stable and had longer lifetimes than parent non-nitro-substituted Fe(II) complex 1. The reaction between FeCl 2 and a sterically less hindered ligand [p-NO 2 -Ph-N=C(Me)-Py-C(Me)=N-Ph-p-NO 2 ] resulted in the formation of octahedral complex 11. A para-dialkylamino-substituted bis(imino)pyridine ligand [p-NEt 2 -o-Me-Ph-N=C(Me)-Py-C(Me)=N-Ph-o-Me-p-NEt2] and the corresponding Fe(II) complex [{p-NEt2-o-Me-Ph-N=C(Me)-Py-C(Me)=N-Ph-o-Me-p-NEt 2 }FeCl 2 (16)] were synthesized to evaluate the effect of enhanced electron donation of the ligand on the catalytic performance. According to X-ray analysis, there was a shortening (up to 0.043 A) of the axial Fe-N bond lengths in para-diethylamino-substituted complex 16 in comparison with parent Fe(II) complex 1.
Databáze: OpenAIRE
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