New bis(allyl)(diketiminato) and tris(allyl) lanthanide complexes and their reactivity in the polymerization of polar monomers

Luis F. Sánchez-Barba; David L. Hughes; Simon M. Humphrey; M. Bochmann

doi:10.1021/om050309x

New bis(allyl)(diketiminato) and tris(allyl) lanthanide complexes and their reactivity in the polymerization of polar monomers

Luis F. Sánchez-Barba
, David L. Hughes
, Simon M. Humphrey
, M. Bochmann

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

110 Citations (Scopus)

Abstract

The reaction of LnCl₃(THF)_n (Ln = La, n = 4; Ln = Y, Sm, Nd, n = 3) with 3 equiv of allylMgCl in THF/1,4-dioxane followed by crystallization in 1,4-dioxane/toluene proceeds in very high yields to give the tris(?³-allyl) complexes [La(?³-C₃H₅)₃(?¹-dioxane)]₂(µ-dioxane) and [Ln(?³-C₃H₅)₃(µ-dioxane)]₈ (Ln = Y, 1; Sm, 2; Nd). Improved one-pot syntheses for the tris(?³-allyl) lanthanum and neodymium compounds are reported. The crystal structures of 1 and 2 show that the compounds consist of distorted square-pyramidal lanthanide centers in linear polymer chains. The reaction of [La(?³-C₃H₅)₃(?¹-dioxane)]₂(µ-dioxane) and [Ln(?³-C₃H₅)₃(µ-dioxane)]₈ with the diketimine ligand 2-(2,6-diisopropylphenyl)amino-4-(2,6-diisopropylphenyl)imino-2-pentene (BDI-H) in THF at 60 °C generates cleanly the ß-diketiminato complexes Ln(?³-C₃H₅)₂{?²-HC(MeCNAr)₂} (Ar = 2,6-C₆H₃ⁱPr₂; Ln = La, 3; Y, 4; Sm, 5; Nd, 6) with propene elimination. The crystal structure of 5 shows a distorted tetrahedral SmN₂(allyl)₂ core, with the samarium atom positioned 1.438(4) Å out of the C₃N₂ ligand plane. All complexes are highly effective single-component catalysts for the ring-opening polymerization of e-caprolactone and rac-lactide. Polymer end group analysis shows that the polymerization process is initiated by allyl transfer to monomer.

Original language	English
Pages (from-to)	3792-3799
Number of pages	8
Journal	Organometallics
Volume	24
Issue number	15
DOIs	https://doi.org/10.1021/om050309x
Publication status	Published - 2005

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10.1021/om050309x

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@article{be42f2db877148af9d2a1e834944c7c3,

title = "New bis(allyl)(diketiminato) and tris(allyl) lanthanide complexes and their reactivity in the polymerization of polar monomers",

abstract = "The reaction of LnCl3(THF)n (Ln = La, n = 4; Ln = Y, Sm, Nd, n = 3) with 3 equiv of allylMgCl in THF/1,4-dioxane followed by crystallization in 1,4-dioxane/toluene proceeds in very high yields to give the tris(?3-allyl) complexes [La(?3-C3H5)3(?1-dioxane)]2(µ-dioxane) and [Ln(?3-C3H5)3(µ-dioxane)]8 (Ln = Y, 1; Sm, 2; Nd). Improved one-pot syntheses for the tris(?3-allyl) lanthanum and neodymium compounds are reported. The crystal structures of 1 and 2 show that the compounds consist of distorted square-pyramidal lanthanide centers in linear polymer chains. The reaction of [La(?3-C3H5)3(?1-dioxane)]2(µ-dioxane) and [Ln(?3-C3H5)3(µ-dioxane)]8 with the diketimine ligand 2-(2,6-diisopropylphenyl)amino-4-(2,6-diisopropylphenyl)imino-2-pentene (BDI-H) in THF at 60 °C generates cleanly the {\ss}-diketiminato complexes Ln(?3-C3H5)2\{?2-HC(MeCNAr)2\} (Ar = 2,6-C6H3iPr2; Ln = La, 3; Y, 4; Sm, 5; Nd, 6) with propene elimination. The crystal structure of 5 shows a distorted tetrahedral SmN2(allyl)2 core, with the samarium atom positioned 1.438(4) {\AA} out of the C3N2 ligand plane. All complexes are highly effective single-component catalysts for the ring-opening polymerization of e-caprolactone and rac-lactide. Polymer end group analysis shows that the polymerization process is initiated by allyl transfer to monomer.",

author = "S{\'a}nchez-Barba, \{Luis F.\} and Hughes, \{David L.\} and Humphrey, \{Simon M.\} and M. Bochmann",

year = "2005",

doi = "10.1021/om050309x",

language = "English",

volume = "24",

pages = "3792--3799",

journal = "Organometallics",

issn = "1520-6041",

publisher = "American Chemical Society",

number = "15",

}

TY - JOUR

T1 - New bis(allyl)(diketiminato) and tris(allyl) lanthanide complexes and their reactivity in the polymerization of polar monomers

AU - Sánchez-Barba, Luis F.

AU - Hughes, David L.

AU - Humphrey, Simon M.

AU - Bochmann, M.

PY - 2005

Y1 - 2005

N2 - The reaction of LnCl3(THF)n (Ln = La, n = 4; Ln = Y, Sm, Nd, n = 3) with 3 equiv of allylMgCl in THF/1,4-dioxane followed by crystallization in 1,4-dioxane/toluene proceeds in very high yields to give the tris(?3-allyl) complexes [La(?3-C3H5)3(?1-dioxane)]2(µ-dioxane) and [Ln(?3-C3H5)3(µ-dioxane)]8 (Ln = Y, 1; Sm, 2; Nd). Improved one-pot syntheses for the tris(?3-allyl) lanthanum and neodymium compounds are reported. The crystal structures of 1 and 2 show that the compounds consist of distorted square-pyramidal lanthanide centers in linear polymer chains. The reaction of [La(?3-C3H5)3(?1-dioxane)]2(µ-dioxane) and [Ln(?3-C3H5)3(µ-dioxane)]8 with the diketimine ligand 2-(2,6-diisopropylphenyl)amino-4-(2,6-diisopropylphenyl)imino-2-pentene (BDI-H) in THF at 60 °C generates cleanly the ß-diketiminato complexes Ln(?3-C3H5)2{?2-HC(MeCNAr)2} (Ar = 2,6-C6H3iPr2; Ln = La, 3; Y, 4; Sm, 5; Nd, 6) with propene elimination. The crystal structure of 5 shows a distorted tetrahedral SmN2(allyl)2 core, with the samarium atom positioned 1.438(4) Å out of the C3N2 ligand plane. All complexes are highly effective single-component catalysts for the ring-opening polymerization of e-caprolactone and rac-lactide. Polymer end group analysis shows that the polymerization process is initiated by allyl transfer to monomer.

AB - The reaction of LnCl3(THF)n (Ln = La, n = 4; Ln = Y, Sm, Nd, n = 3) with 3 equiv of allylMgCl in THF/1,4-dioxane followed by crystallization in 1,4-dioxane/toluene proceeds in very high yields to give the tris(?3-allyl) complexes [La(?3-C3H5)3(?1-dioxane)]2(µ-dioxane) and [Ln(?3-C3H5)3(µ-dioxane)]8 (Ln = Y, 1; Sm, 2; Nd). Improved one-pot syntheses for the tris(?3-allyl) lanthanum and neodymium compounds are reported. The crystal structures of 1 and 2 show that the compounds consist of distorted square-pyramidal lanthanide centers in linear polymer chains. The reaction of [La(?3-C3H5)3(?1-dioxane)]2(µ-dioxane) and [Ln(?3-C3H5)3(µ-dioxane)]8 with the diketimine ligand 2-(2,6-diisopropylphenyl)amino-4-(2,6-diisopropylphenyl)imino-2-pentene (BDI-H) in THF at 60 °C generates cleanly the ß-diketiminato complexes Ln(?3-C3H5)2{?2-HC(MeCNAr)2} (Ar = 2,6-C6H3iPr2; Ln = La, 3; Y, 4; Sm, 5; Nd, 6) with propene elimination. The crystal structure of 5 shows a distorted tetrahedral SmN2(allyl)2 core, with the samarium atom positioned 1.438(4) Å out of the C3N2 ligand plane. All complexes are highly effective single-component catalysts for the ring-opening polymerization of e-caprolactone and rac-lactide. Polymer end group analysis shows that the polymerization process is initiated by allyl transfer to monomer.

U2 - 10.1021/om050309x

DO - 10.1021/om050309x

M3 - Article

SN - 1520-6041

VL - 24

SP - 3792

EP - 3799

JO - Organometallics

JF - Organometallics

IS - 15

ER -