Synthesis and Characterization of Iron, Cobalt, and Nickel Complexes Bearing Novel <i>N</i>,<i>N</i>‐Chelate Ligands and Their Catalytic Properties in Ethylene Oligomerization

Wang, Li; Zhang, Cheng; Wang, Zhong‐Xia

doi:10.1002/ejic.200700020

Cited by 22 publications

(10 citation statements)

References 63 publications

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“…The four-coordinated nickel atom has a distorted tetrahedral coordination geometry and is coplanar with the N1C5C6N2 plane. The Ni-N1 distance of 1.981(4) Å is slightly longer than the corresponding value in P,N(quinolyl)-chelate nickel complex Ni 20 The P1-N2 distance of 1.601(3) Å is a little longer than a P-N double bond which is about 1.57 Å, and the P1-N3 distance of 1.641(4) Å is between a formal P-N single (1.77 Å) and double bond. 21 Complex 4 is a deep red diamagnetic crystalline solid which was characterized by elemental analysis, 1 H, 13 C and 31 P NMR and IR spectroscopy.…”

Section: Synthesis and Characterization Of Ligands And Complexesmentioning

confidence: 69%

Nickel complexes supported by quinoline-based ligands: synthesis, characterization and catalysis in the cross-coupling of arylzinc reagents and aryl chlorides or aryltrimethylammonium salts

Zhang

Wang

2012

Dalton Trans.

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Lithium and nickel complexes bearing quinoline-based ligands have been synthesized and characterized. Reaction of 8-azidoquinoline with Ph(2)PNHR (R = p-MeC(6)H(4), Bu(t)) affords N-(8-quinolyl)iminophosphoranes RNHP(Ph(2))=N(8-C(9)H(6)N) (1a, R = p-MeC(6)H(4); 1b, R = Bu(t). C(9)H(6)N = quinolyl)). Reaction of 1a with (DME)NiCl(2) generates a nickel complex [NiCl(2){N(8-C(9)H(6)N)=P(Ph(2))NH(p-MeC(6)H(4))}] (2a). Treatment of 1b with (DME)NiCl(2) and following with NaH produces [NiCl{(1,2-C(6)H(4))P(Ph)(NHBu(t))=N(8-C(9)H(6)N)}] (4). Complex 4 was also obtained by reaction of (DME)NiCl(2) with [Li{(1,2-C(6)H(4))P(Ph)(NHBu(t))=N(8-C(9)H(6)N)}] (5) prepared through lithiation of 1b. Reaction of 2-PyCH(2)P(Ph(2))=N(8-C(9)H(6)N) (6, Py = pyridyl) and PhN=C(Ph)CH(2)P(Ph(2))=N(8-C(9)H(6)N) (8), respectively, with (DME)NiCl(2) yields two five-coordinate N,N,N-chelate nickel complexes, [NiCl(2){2-PyCH(2)P(Ph(2))=N(8-C(9)H(6)N)}] (7) and [NiCl(2){PhN=C(Ph)CH(2)P(Ph(2))=N(8-C(9)H(6)N)}] (9). Similar reaction between Ph(2)PCH(2)P(Ph(2))=N(8-C(9)H(6)N) (10) and (DME)NiCl(2) results in five-coordinate N,N,P-chelate nickel complex [NiCl(2){Ph(2)PCH(2)P(Ph(2))=N(8-C(9)H(6)N)}] (11). Treatment of [(8-C(9)H(6)N)N=P(Ph(2))](2)CH(2) (12) [prepared from (Ph(2)P)(2)CH(2) and 2 equiv. of 8-azidoquinoline] with LiBu(n) and (DME)NiCl(2) successively affords [NiCl{(8-C(9)H(6)N)NP(Ph(2))}(2)CH] (13). The new compounds were characterized by (1)H, (13)C and (31)P NMR spectroscopy (for the diamagnetic compounds), IR spectroscopy (for the nickel complexes) and elemental analysis. Complexes 2a, 4, 7, 9, 11 and 13 were also characterized by single-crystal X-ray diffraction techniques. The nickel complexes were evaluated for the catalysis in the cross-coupling reactions of arylzinc reagents with aryl chlorides and aryltrimethylammonium salts. Complex 7 exhibits the highest activity among the complexes in catalyzing the reactions of arylzinc reagents with either aryl chlorides or aryltrimethylammonium bromides.

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Section: Synthesis and Characterization Of Ligands And Complexesmentioning

confidence: 69%

Nickel complexes supported by quinoline-based ligands: synthesis, characterization and catalysis in the cross-coupling of arylzinc reagents and aryl chlorides or aryltrimethylammonium salts

Zhang

Wang

2012

Dalton Trans.

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“…Scheme 1 N,N-bi-dentate iron and cobalt complexes 24 Kempe et al have investigated the 6-aryl-substituted N,Nbi-dentate iron and cobalt complexes 6-9 (Scheme 2) for ethylene oligomerization. 31 In the case of the iron complexes 6 and 8, scant activity was observed (entries 1 − 4, Table 2), 50 whereas systems 7 and 9 exhibited high selectivity towards 1-butene (entries 5 − 8, Table 2).…”

Section: Bi-dentate Iron and Cobalt Pre-catalystsmentioning

confidence: 99%

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

Feng

Wang

et al. 2014

Inorg. Chem. Front.

120

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Recent progress on the use of iron and cobalt complex precatalysts for ethylene reactivity is reviewed. The review is organized in terms of the denticity of the chelate ligands 10 employed, with particular reference to the influence of the ligand frameworks and their substituents on the catalytic performance for ethylene oligomerization/polymerization catalysis. The majority of the systems bear tri-dentate ligation at the iron/cobalt centre, though it is clear that bi-dentate 15 iron/cobalt complex pre-catalysts have also attracted significant attention. Such systems produce in most cases highly linear products ranging from oligomeric α-olefins to high molecular weight polyethylene, and as such are promising candidates for both academic and industrial 20 considerations.

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“…of MMAO (5.5 Â 10 5 g (mol h atm) À1 under 1 atm and at 20 1C). 57 Sun and co-workers prepared a series of 2-(ethylcarboxylato)-6-iminopyridyl complexes from ligands 45. 58 Ferrous complexes were characterized by FT-IR spectroscopy.…”

Section: Pendant Donor A-diimine Ligandsmentioning

confidence: 99%

“…The same behaviour was observed with ligands 53 developed by Kempe et al 62 New bidentate bis(imino)cyclodisphophazane ligands 54 led to inactive systems when associated with an iron centre. 63 Sun and co-workers have developed a range of bidentate ligands based on quinoxaline 55 64 and quinoline ligands (56)(57)(58). [65][66][67] The iron complex containing 2-(2-pyridyl)quinoxaline ligands gave only marginal activity.…”

Section: Pendant Donor A-diimine Ligandsmentioning

confidence: 99%

Ethylene oligomerization using iron complexes: beyond the discovery of bis(imino)pyridine ligands

et al. 2014

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Since the discovery that bis(imino)pyridine ligands are able to confer high activities in ethylene oligomerization and polymerization to their iron complexes, considerable attention has been focused on catalyst design for these reactions and this research constitutes an ever-growing area in molecular catalysis. The tuning of the ligand structures and properties, and thus of catalysts, generally represents the basis for subsequent work contributing to process development and industrialization. Significant effort is therefore devoted to generate structural diversity in order to access the required catalyst stability and selectivity. This feature article outlines nitrogen-containing ligands that have been developed for the iron-catalyzed oligomerization of ethylene since the seminal discovery of the properties of bis(imino)pyridine ligands.

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Synthesis and Characterization of Iron, Cobalt, and Nickel Complexes Bearing Novel N,N‐Chelate Ligands and Their Catalytic Properties in Ethylene Oligomerization

Abstract: Treatment of o-ROC

Cited by 22 publications

References 63 publications

Nickel complexes supported by quinoline-based ligands: synthesis, characterization and catalysis in the cross-coupling of arylzinc reagents and aryl chlorides or aryltrimethylammonium salts

Nickel complexes supported by quinoline-based ligands: synthesis, characterization and catalysis in the cross-coupling of arylzinc reagents and aryl chlorides or aryltrimethylammonium salts

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

Ethylene oligomerization using iron complexes: beyond the discovery of bis(imino)pyridine ligands

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