Synthesis and reactivity of sterically hindered iminopyrrolato complexes of zirconium, iron, cobalt and nickel

David M. Dawson; Dennis A. Walker; Mark Thornton-Pett; Manfred Bochmann

doi:10.1039/a909125d

Synthesis and reactivity of sterically hindered iminopyrrolato complexes of zirconium, iron, cobalt and nickel

David M. Dawson, Dennis A. Walker, Mark Thornton-Pett, Manfred Bochmann

Research output: Contribution to journal › Article › peer-review

10 Citations (Scopus)

Abstract

The new bis(imino)pyrrole ligand 2,5-C₄H₂NH(CH==NC₆H₃Prⁱ₂)₂ (HL¹) reacts with Zr(NMe₂)₄ to give the 1:1 complex (L¹)Zr(NMe₂)₃ (1), whereas the mono(imino)pyrrole 2-C₄H₃NH(CH==NC₆H₃Prⁱ₂) (HL²) substitutes two amido ligands to give (L²)₂Zr(NMe₂)₂ (2). The lithium salt LiL¹ reacts with ZrCl₄ to give (L¹)ZrCl₂(µ-Cl)₂Li(OEt₂)₂ (3), while the reaction of LiL² with ZrCl₄ or treating 2 with Me₃SiCl gives (L²)₂ZrCl₂. Iron(II) chloride reacts with LiL¹ to afford the bis(ligand) complex Fe(L¹)₂ (5), while only one pyrrolato ligand is incorporated on reacting LiL¹ with CoCl₂(thf) to give [Li(thf)₄][CoCl₂L¹] (6a). On warming, 6a readily loses thf to give [Li(thf)₂][CoCl₂L¹] (6b). By contrast, LiL² reacts with CoCl₂ and NiCl₂ to give the halide-free complexes Co(L²)₂ and Ni(L²)₂, respectively. The crystal structures of HL¹ and complexes 1, 2 and 5 are reported. In all cases the potentially tridentate ligand L¹ is two-coordinate. Mixtures of the halide-free bis(ligand) complexes with methylaluminoxane do not show any activity for ethene polymerisation; however, 3 and 4 catalyse the polymerisation of ethene, while 6 has moderate activity for the oligomerisation of ethene and propene to linear and branched products.

Original language	English
Pages (from-to)	459-466
Number of pages	8
Journal	Journal of the Chemical Society, Dalton Transactions
Issue number	4
DOIs	https://doi.org/10.1039/a909125d
Publication status	Published - 2000

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10.1039/a909125d

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@article{330ac1c5a36f4dc082e506968e73177b,

title = "Synthesis and reactivity of sterically hindered iminopyrrolato complexes of zirconium, iron, cobalt and nickel",

abstract = "The new bis(imino)pyrrole ligand 2,5-C4H2NH(CH==NC6H3Pri2)2 (HL1) reacts with Zr(NMe2)4 to give the 1:1 complex (L1)Zr(NMe2)3 (1), whereas the mono(imino)pyrrole 2-C4H3NH(CH==NC6H3Pri2) (HL2) substitutes two amido ligands to give (L2)2Zr(NMe2)2 (2). The lithium salt LiL1 reacts with ZrCl4 to give (L1)ZrCl2(µ-Cl)2Li(OEt2)2 (3), while the reaction of LiL2 with ZrCl4 or treating 2 with Me3SiCl gives (L2)2ZrCl2. Iron(II) chloride reacts with LiL1 to afford the bis(ligand) complex Fe(L1)2 (5), while only one pyrrolato ligand is incorporated on reacting LiL1 with CoCl2(thf) to give [Li(thf)4][CoCl2L1] (6a). On warming, 6a readily loses thf to give [Li(thf)2][CoCl2L1] (6b). By contrast, LiL2 reacts with CoCl2 and NiCl2 to give the halide-free complexes Co(L2)2 and Ni(L2)2, respectively. The crystal structures of HL1 and complexes 1, 2 and 5 are reported. In all cases the potentially tridentate ligand L1 is two-coordinate. Mixtures of the halide-free bis(ligand) complexes with methylaluminoxane do not show any activity for ethene polymerisation; however, 3 and 4 catalyse the polymerisation of ethene, while 6 has moderate activity for the oligomerisation of ethene and propene to linear and branched products.",

author = "Dawson, {David M.} and Walker, {Dennis A.} and Mark Thornton-Pett and Manfred Bochmann",

year = "2000",

doi = "10.1039/a909125d",

language = "English",

pages = "459--466",

journal = "Dalton Transactions",

issn = "1477-9226",

publisher = "Royal Society of Chemistry",

number = "4",

}

TY - JOUR

T1 - Synthesis and reactivity of sterically hindered iminopyrrolato complexes of zirconium, iron, cobalt and nickel

AU - Dawson, David M.

AU - Walker, Dennis A.

AU - Thornton-Pett, Mark

AU - Bochmann, Manfred

PY - 2000

Y1 - 2000

N2 - The new bis(imino)pyrrole ligand 2,5-C4H2NH(CH==NC6H3Pri2)2 (HL1) reacts with Zr(NMe2)4 to give the 1:1 complex (L1)Zr(NMe2)3 (1), whereas the mono(imino)pyrrole 2-C4H3NH(CH==NC6H3Pri2) (HL2) substitutes two amido ligands to give (L2)2Zr(NMe2)2 (2). The lithium salt LiL1 reacts with ZrCl4 to give (L1)ZrCl2(µ-Cl)2Li(OEt2)2 (3), while the reaction of LiL2 with ZrCl4 or treating 2 with Me3SiCl gives (L2)2ZrCl2. Iron(II) chloride reacts with LiL1 to afford the bis(ligand) complex Fe(L1)2 (5), while only one pyrrolato ligand is incorporated on reacting LiL1 with CoCl2(thf) to give [Li(thf)4][CoCl2L1] (6a). On warming, 6a readily loses thf to give [Li(thf)2][CoCl2L1] (6b). By contrast, LiL2 reacts with CoCl2 and NiCl2 to give the halide-free complexes Co(L2)2 and Ni(L2)2, respectively. The crystal structures of HL1 and complexes 1, 2 and 5 are reported. In all cases the potentially tridentate ligand L1 is two-coordinate. Mixtures of the halide-free bis(ligand) complexes with methylaluminoxane do not show any activity for ethene polymerisation; however, 3 and 4 catalyse the polymerisation of ethene, while 6 has moderate activity for the oligomerisation of ethene and propene to linear and branched products.

AB - The new bis(imino)pyrrole ligand 2,5-C4H2NH(CH==NC6H3Pri2)2 (HL1) reacts with Zr(NMe2)4 to give the 1:1 complex (L1)Zr(NMe2)3 (1), whereas the mono(imino)pyrrole 2-C4H3NH(CH==NC6H3Pri2) (HL2) substitutes two amido ligands to give (L2)2Zr(NMe2)2 (2). The lithium salt LiL1 reacts with ZrCl4 to give (L1)ZrCl2(µ-Cl)2Li(OEt2)2 (3), while the reaction of LiL2 with ZrCl4 or treating 2 with Me3SiCl gives (L2)2ZrCl2. Iron(II) chloride reacts with LiL1 to afford the bis(ligand) complex Fe(L1)2 (5), while only one pyrrolato ligand is incorporated on reacting LiL1 with CoCl2(thf) to give [Li(thf)4][CoCl2L1] (6a). On warming, 6a readily loses thf to give [Li(thf)2][CoCl2L1] (6b). By contrast, LiL2 reacts with CoCl2 and NiCl2 to give the halide-free complexes Co(L2)2 and Ni(L2)2, respectively. The crystal structures of HL1 and complexes 1, 2 and 5 are reported. In all cases the potentially tridentate ligand L1 is two-coordinate. Mixtures of the halide-free bis(ligand) complexes with methylaluminoxane do not show any activity for ethene polymerisation; however, 3 and 4 catalyse the polymerisation of ethene, while 6 has moderate activity for the oligomerisation of ethene and propene to linear and branched products.

U2 - 10.1039/a909125d

DO - 10.1039/a909125d

M3 - Article

SP - 459

EP - 466

JO - Dalton Transactions

JF - Dalton Transactions

SN - 1477-9226

IS - 4

ER -