Lanthanide/actinide differentiation with sterically encumbered N-heterocyclic carbene ligands

Polly L. Arnold; Zoe R. Turner; Anne I. Germeroth; Ian J. Casely; Ronan Bellabarba; Robert P. Tooze

doi:10.1039/c001584a

Lanthanide/actinide differentiation with sterically encumbered N-heterocyclic carbene ligands

Polly L. Arnold, Zoe R. Turner, Anne I. Germeroth, Ian J. Casely, Ronan Bellabarba, Robert P. Tooze

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

Abstract

A study is reported on the relative stability of trivalent bis(ligand) complexes of the form [M(L^R)₂N''] for trivalent group 3, lanthanide and actinide cations, using the sterically demanding N-heterocyclic carbene ligand L^R = [OCMe₂CH₂{CNCH₂CH₂NR}] (R = ⁱPrL^{P, Mes L^M, Dipp L^D; N'' = N(SiMe₃)₂). For the small Y^IIIcation (r_6-coord = 1.040}Å) and the smallest L^{R, R = ⁱPr, mono, bis, and tris(L^P) complexes can be made; [Y(L^P)₂N''] and [Y(L^P)₃] have been characterised. For the larger ligands, L^M and L^D, only the mono(L^R) complexes [Y(L^M)N''₂] and [Y(L^D)N''₂] can be made. For the larger Ce^III (r_6-coord = 1.15}Å), mono(L^R) and bis(L^R) complexes [Ce(L^M)N''₂], [Ce(L^D)N''₂], [Ce(L^M)₂N''], and [Ce(L^D)₂N''] can be made; structural characterisation of the latter two confirm the high degree of steric congestion. The new complex [U(L^M)N''₂] has also been isolated. Despite the very similar radii of Ce^III and U^III (r_6-coord = 1.165 Å), the complexes [U(L^{R)₂N''] cannot be isolated; a surprising display of the difference between the 4f and 5f metal series. However, the six-coordinate, bis(ligand) U^IV complexes can readily be isolated if smaller ancillary ligands are used; [U(L^M)₂I₂] and [U(L^D)₂I₂] have been fully, including structurally, characterised.}

Original language	English
Pages (from-to)	6808-6814
Number of pages	7
Journal	Dalton Transactions
Volume	39
Issue number	29
Early online date	4 Jun 2010
DOIs	https://doi.org/10.1039/c001584a
Publication status	Published - 7 Aug 2010

Keywords / Materials (for Non-textual outputs)

CRYSTAL-STRUCTURE
ETHYLENE OLIGOMERIZATION
COORDINATION CHEMISTRY
TRANSITION-METALS
NHC CATALYSTS
COMPLEXES
POLYMERIZATION
REACTIVITY
URANIUM
BOND

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10.1039/c001584a

Lanthanideactinide differentiation with sterically encumbered N-heterocyclic carbene ligands
Copyright © 2010 by the Royal Society of Chemistry. All rights reserved.
Accepted author manuscript, 650 KB

http://pubs.rsc.org/en/content/articlehtml/2010/dt/c001584a

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@article{4348be412c9a4c4e9f418218bbbea734,

title = "Lanthanide/actinide differentiation with sterically encumbered N-heterocyclic carbene ligands",

abstract = "A study is reported on the relative stability of trivalent bis(ligand) complexes of the form [M(LR)2N''] for trivalent group 3, lanthanide and actinide cations, using the sterically demanding N-heterocyclic carbene ligand LR = [OCMe2CH2{CNCH2CH2NR}] (R = iPrLP, Mes LM, Dipp LD; N'' = N(SiMe3)2). For the small YIII cation (r6-coord = 1.040 {\AA}) and the smallest LR, R = iPr, mono, bis, and tris(LP) complexes can be made; [Y(LP)2N''] and [Y(LP)3] have been characterised. For the larger ligands, LM and LD, only the mono(LR) complexes [Y(LM)N''2] and [Y(LD)N''2] can be made. For the larger CeIII (r6-coord = 1.15 {\AA}), mono(LR) and bis(LR) complexes [Ce(LM)N''2], [Ce(LD)N''2], [Ce(LM)2N''], and [Ce(LD)2N''] can be made; structural characterisation of the latter two confirm the high degree of steric congestion. The new complex [U(LM)N''2] has also been isolated. Despite the very similar radii of CeIII and UIII (r6-coord = 1.165 {\AA}), the complexes [U(LR)2N''] cannot be isolated; a surprising display of the difference between the 4f and 5f metal series. However, the six-coordinate, bis(ligand) UIV complexes can readily be isolated if smaller ancillary ligands are used; [U(LM)2I2] and [U(LD)2I2] have been fully, including structurally, characterised.",

keywords = "CRYSTAL-STRUCTURE, ETHYLENE OLIGOMERIZATION, COORDINATION CHEMISTRY, TRANSITION-METALS, NHC CATALYSTS, COMPLEXES, POLYMERIZATION, REACTIVITY, URANIUM, BOND",

author = "Arnold, {Polly L.} and Turner, {Zoe R.} and Germeroth, {Anne I.} and Casely, {Ian J.} and Ronan Bellabarba and Tooze, {Robert P.}",

year = "2010",

month = aug,

day = "7",

doi = "10.1039/c001584a",

language = "English",

volume = "39",

pages = "6808--6814",

journal = "Dalton Transactions",

issn = "1477-9226",

publisher = "Royal Society of Chemistry",

number = "29",

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TY - JOUR

T1 - Lanthanide/actinide differentiation with sterically encumbered N-heterocyclic carbene ligands

AU - Arnold, Polly L.

AU - Turner, Zoe R.

AU - Germeroth, Anne I.

AU - Casely, Ian J.

AU - Bellabarba, Ronan

AU - Tooze, Robert P.

PY - 2010/8/7

Y1 - 2010/8/7

N2 - A study is reported on the relative stability of trivalent bis(ligand) complexes of the form [M(LR)2N''] for trivalent group 3, lanthanide and actinide cations, using the sterically demanding N-heterocyclic carbene ligand LR = [OCMe2CH2{CNCH2CH2NR}] (R = iPrLP, Mes LM, Dipp LD; N'' = N(SiMe3)2). For the small YIII cation (r6-coord = 1.040 Å) and the smallest LR, R = iPr, mono, bis, and tris(LP) complexes can be made; [Y(LP)2N''] and [Y(LP)3] have been characterised. For the larger ligands, LM and LD, only the mono(LR) complexes [Y(LM)N''2] and [Y(LD)N''2] can be made. For the larger CeIII (r6-coord = 1.15 Å), mono(LR) and bis(LR) complexes [Ce(LM)N''2], [Ce(LD)N''2], [Ce(LM)2N''], and [Ce(LD)2N''] can be made; structural characterisation of the latter two confirm the high degree of steric congestion. The new complex [U(LM)N''2] has also been isolated. Despite the very similar radii of CeIII and UIII (r6-coord = 1.165 Å), the complexes [U(LR)2N''] cannot be isolated; a surprising display of the difference between the 4f and 5f metal series. However, the six-coordinate, bis(ligand) UIV complexes can readily be isolated if smaller ancillary ligands are used; [U(LM)2I2] and [U(LD)2I2] have been fully, including structurally, characterised.

AB - A study is reported on the relative stability of trivalent bis(ligand) complexes of the form [M(LR)2N''] for trivalent group 3, lanthanide and actinide cations, using the sterically demanding N-heterocyclic carbene ligand LR = [OCMe2CH2{CNCH2CH2NR}] (R = iPrLP, Mes LM, Dipp LD; N'' = N(SiMe3)2). For the small YIII cation (r6-coord = 1.040 Å) and the smallest LR, R = iPr, mono, bis, and tris(LP) complexes can be made; [Y(LP)2N''] and [Y(LP)3] have been characterised. For the larger ligands, LM and LD, only the mono(LR) complexes [Y(LM)N''2] and [Y(LD)N''2] can be made. For the larger CeIII (r6-coord = 1.15 Å), mono(LR) and bis(LR) complexes [Ce(LM)N''2], [Ce(LD)N''2], [Ce(LM)2N''], and [Ce(LD)2N''] can be made; structural characterisation of the latter two confirm the high degree of steric congestion. The new complex [U(LM)N''2] has also been isolated. Despite the very similar radii of CeIII and UIII (r6-coord = 1.165 Å), the complexes [U(LR)2N''] cannot be isolated; a surprising display of the difference between the 4f and 5f metal series. However, the six-coordinate, bis(ligand) UIV complexes can readily be isolated if smaller ancillary ligands are used; [U(LM)2I2] and [U(LD)2I2] have been fully, including structurally, characterised.

KW - CRYSTAL-STRUCTURE

KW - ETHYLENE OLIGOMERIZATION

KW - COORDINATION CHEMISTRY

KW - TRANSITION-METALS

KW - NHC CATALYSTS

KW - COMPLEXES

KW - POLYMERIZATION

KW - REACTIVITY

KW - URANIUM

KW - BOND

U2 - 10.1039/c001584a

DO - 10.1039/c001584a

M3 - Article

SN - 1477-9226

VL - 39

SP - 6808

EP - 6814

JO - Dalton Transactions

JF - Dalton Transactions

IS - 29

ER -

Lanthanide/actinide differentiation with sterically encumbered N-heterocyclic carbene ligands

Abstract

Keywords / Materials (for Non-textual outputs)

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