Synthesis and structural characterisation of rhodium hydride complexes bearing N-heterocyclic carbene ligands

Susie Douglas, John P Lowe, Mary F Mahon, John E Warren, Michael K Whittlesey

Research output: Contribution to journalArticle

  • 18 Citations

Abstract

Addn. of excesses of N-heterocyclic carbenes (NHCs) IEt2Me2, IiPr2Me2 or ICy (IEt2Me2 = 1,3-diethyl-4,5-dimethylimidazol-2-ylidene; IiPr2Me2 = 1,3-diisopropyl-4,5-dimethylimidazol-2-ylidene; ICy = 1,3-dicyclohexylimidazol-2-ylidene) to [HRh(PPh3)4] (1) affords an isomeric mixt. of [HRh(NHC)(PPh3)2] [NHC = IEt2Me2 (cis-/trans-2), IiPr2Me2 (cis-/trans-3), ICy (cis-/trans-4)] and [HRh(NHC)2(PPh3)] [NHC = IEt2Me2(cis-/trans-5), IiPr2Me2 (cis-/trans-6), ICy (cis-/trans-7)]. Thermolysis of 1 with the aryl substituted NHC, 1,3-dimesityl-4,5-dihydroimidazol-2-ylidene (IMesH2), affords the bridging hydrido phosphido dimer, [{(PPh3)2Rh}2(micro -H)(micro -PPh2)] (8), which is also the reaction product formed in the absence of carbene. When the Rh precursor was changed from 1 to [HRh(CO)(PPh3)3] (9) and treated with either IMes (1,3-dimesitylimidazol-2-ylidene) or ICy, the bis-NHC complexes trans-[HRh(CO)(IMes)2] (10) and trans-[HRh(CO)(ICy)2] (11) were formed. In contrast, the reaction of 9 with IiPr2Me2 gave [HRh(CO)(IiPr2Me2)2] (cis-/trans-12) and the unusual unsym. dimer, [(PPh3)2Rh(micro -CO)2Rh(IiPr2Me2)2] (13). Trans-3, 8, 10 and 13 were structurally characterized.
LanguageEnglish
Pages5027-5035
Number of pages9
JournalJournal of Organometallic Chemistry
Volume690
Issue number23
StatusPublished - 2005

Fingerprint

Bearings (structural)
Rhodium
carbenes
rhodium
Hydrides
Dimers
hydrides
Ligands
Carbon Monoxide
Thermolysis
ligands
synthesis
Reaction products
dimers
carbene
reaction products

Keywords

  • Molecular structure (of rhodium hydride complexes with N-heterocyclic carbene imidazolylidene ligands)
  • Diastereomers (geometric
  • mol structure rhodium hydride heterocyclic carbene imidazolylidene ligand
  • PREP (Preparation) (prepn. and structure of rhodium hydride complexes with N-heterocyclic carbene imidazolylidene ligands)
  • PRP (Properties)
  • RCT (Reactant)
  • rhodium hydride heterocyclic carbene imidazolylidene ligand prepn structure
  • crystal structure rhodium hydride heterocyclic carbene imidazolylidene ligand prepn
  • RACT (Reactant or reagent) (nitrogen
  • prepn. and structure of rhodium hydride complexes with N-heterocyclic carbene imidazolylidene ligands)
  • five-membered-ring
  • Crystal structure
  • Heterocyclic compounds Role
  • Carbene complexes Role
  • SPN (Synthetic preparation)

Cite this

@article{d507b0885065492c86409ab1c21ac8a5,
title = "Synthesis and structural characterisation of rhodium hydride complexes bearing N-heterocyclic carbene ligands",
abstract = "Addn. of excesses of N-heterocyclic carbenes (NHCs) IEt2Me2, IiPr2Me2 or ICy (IEt2Me2 = 1,3-diethyl-4,5-dimethylimidazol-2-ylidene; IiPr2Me2 = 1,3-diisopropyl-4,5-dimethylimidazol-2-ylidene; ICy = 1,3-dicyclohexylimidazol-2-ylidene) to [HRh(PPh3)4] (1) affords an isomeric mixt. of [HRh(NHC)(PPh3)2] [NHC = IEt2Me2 (cis-/trans-2), IiPr2Me2 (cis-/trans-3), ICy (cis-/trans-4)] and [HRh(NHC)2(PPh3)] [NHC = IEt2Me2(cis-/trans-5), IiPr2Me2 (cis-/trans-6), ICy (cis-/trans-7)]. Thermolysis of 1 with the aryl substituted NHC, 1,3-dimesityl-4,5-dihydroimidazol-2-ylidene (IMesH2), affords the bridging hydrido phosphido dimer, [{(PPh3)2Rh}2(micro -H)(micro -PPh2)] (8), which is also the reaction product formed in the absence of carbene. When the Rh precursor was changed from 1 to [HRh(CO)(PPh3)3] (9) and treated with either IMes (1,3-dimesitylimidazol-2-ylidene) or ICy, the bis-NHC complexes trans-[HRh(CO)(IMes)2] (10) and trans-[HRh(CO)(ICy)2] (11) were formed. In contrast, the reaction of 9 with IiPr2Me2 gave [HRh(CO)(IiPr2Me2)2] (cis-/trans-12) and the unusual unsym. dimer, [(PPh3)2Rh(micro -CO)2Rh(IiPr2Me2)2] (13). Trans-3, 8, 10 and 13 were structurally characterized.",
keywords = "Molecular structure (of rhodium hydride complexes with N-heterocyclic carbene imidazolylidene ligands), Diastereomers (geometric, mol structure rhodium hydride heterocyclic carbene imidazolylidene ligand, PREP (Preparation) (prepn. and structure of rhodium hydride complexes with N-heterocyclic carbene imidazolylidene ligands), PRP (Properties), RCT (Reactant), rhodium hydride heterocyclic carbene imidazolylidene ligand prepn structure, crystal structure rhodium hydride heterocyclic carbene imidazolylidene ligand prepn, RACT (Reactant or reagent) (nitrogen, prepn. and structure of rhodium hydride complexes with N-heterocyclic carbene imidazolylidene ligands), five-membered-ring, Crystal structure, Heterocyclic compounds Role, Carbene complexes Role, SPN (Synthetic preparation)",
author = "Susie Douglas and Lowe, {John P} and Mahon, {Mary F} and Warren, {John E} and Whittlesey, {Michael K}",
year = "2005",
language = "English",
volume = "690",
pages = "5027--5035",
journal = "Journal of Organometallic Chemistry",
issn = "0022-328X",
publisher = "Elsevier",
number = "23",

}

TY - JOUR

T1 - Synthesis and structural characterisation of rhodium hydride complexes bearing N-heterocyclic carbene ligands

AU - Douglas,Susie

AU - Lowe,John P

AU - Mahon,Mary F

AU - Warren,John E

AU - Whittlesey,Michael K

PY - 2005

Y1 - 2005

N2 - Addn. of excesses of N-heterocyclic carbenes (NHCs) IEt2Me2, IiPr2Me2 or ICy (IEt2Me2 = 1,3-diethyl-4,5-dimethylimidazol-2-ylidene; IiPr2Me2 = 1,3-diisopropyl-4,5-dimethylimidazol-2-ylidene; ICy = 1,3-dicyclohexylimidazol-2-ylidene) to [HRh(PPh3)4] (1) affords an isomeric mixt. of [HRh(NHC)(PPh3)2] [NHC = IEt2Me2 (cis-/trans-2), IiPr2Me2 (cis-/trans-3), ICy (cis-/trans-4)] and [HRh(NHC)2(PPh3)] [NHC = IEt2Me2(cis-/trans-5), IiPr2Me2 (cis-/trans-6), ICy (cis-/trans-7)]. Thermolysis of 1 with the aryl substituted NHC, 1,3-dimesityl-4,5-dihydroimidazol-2-ylidene (IMesH2), affords the bridging hydrido phosphido dimer, [{(PPh3)2Rh}2(micro -H)(micro -PPh2)] (8), which is also the reaction product formed in the absence of carbene. When the Rh precursor was changed from 1 to [HRh(CO)(PPh3)3] (9) and treated with either IMes (1,3-dimesitylimidazol-2-ylidene) or ICy, the bis-NHC complexes trans-[HRh(CO)(IMes)2] (10) and trans-[HRh(CO)(ICy)2] (11) were formed. In contrast, the reaction of 9 with IiPr2Me2 gave [HRh(CO)(IiPr2Me2)2] (cis-/trans-12) and the unusual unsym. dimer, [(PPh3)2Rh(micro -CO)2Rh(IiPr2Me2)2] (13). Trans-3, 8, 10 and 13 were structurally characterized.

AB - Addn. of excesses of N-heterocyclic carbenes (NHCs) IEt2Me2, IiPr2Me2 or ICy (IEt2Me2 = 1,3-diethyl-4,5-dimethylimidazol-2-ylidene; IiPr2Me2 = 1,3-diisopropyl-4,5-dimethylimidazol-2-ylidene; ICy = 1,3-dicyclohexylimidazol-2-ylidene) to [HRh(PPh3)4] (1) affords an isomeric mixt. of [HRh(NHC)(PPh3)2] [NHC = IEt2Me2 (cis-/trans-2), IiPr2Me2 (cis-/trans-3), ICy (cis-/trans-4)] and [HRh(NHC)2(PPh3)] [NHC = IEt2Me2(cis-/trans-5), IiPr2Me2 (cis-/trans-6), ICy (cis-/trans-7)]. Thermolysis of 1 with the aryl substituted NHC, 1,3-dimesityl-4,5-dihydroimidazol-2-ylidene (IMesH2), affords the bridging hydrido phosphido dimer, [{(PPh3)2Rh}2(micro -H)(micro -PPh2)] (8), which is also the reaction product formed in the absence of carbene. When the Rh precursor was changed from 1 to [HRh(CO)(PPh3)3] (9) and treated with either IMes (1,3-dimesitylimidazol-2-ylidene) or ICy, the bis-NHC complexes trans-[HRh(CO)(IMes)2] (10) and trans-[HRh(CO)(ICy)2] (11) were formed. In contrast, the reaction of 9 with IiPr2Me2 gave [HRh(CO)(IiPr2Me2)2] (cis-/trans-12) and the unusual unsym. dimer, [(PPh3)2Rh(micro -CO)2Rh(IiPr2Me2)2] (13). Trans-3, 8, 10 and 13 were structurally characterized.

KW - Molecular structure (of rhodium hydride complexes with N-heterocyclic carbene imidazolylidene ligands)

KW - Diastereomers (geometric

KW - mol structure rhodium hydride heterocyclic carbene imidazolylidene ligand

KW - PREP (Preparation) (prepn. and structure of rhodium hydride complexes with N-heterocyclic carbene imidazolylidene ligands)

KW - PRP (Properties)

KW - RCT (Reactant)

KW - rhodium hydride heterocyclic carbene imidazolylidene ligand prepn structure

KW - crystal structure rhodium hydride heterocyclic carbene imidazolylidene ligand prepn

KW - RACT (Reactant or reagent) (nitrogen

KW - prepn. and structure of rhodium hydride complexes with N-heterocyclic carbene imidazolylidene ligands)

KW - five-membered-ring

KW - Crystal structure

KW - Heterocyclic compounds Role

KW - Carbene complexes Role

KW - SPN (Synthetic preparation)

M3 - Article

VL - 690

SP - 5027

EP - 5035

JO - Journal of Organometallic Chemistry

T2 - Journal of Organometallic Chemistry

JF - Journal of Organometallic Chemistry

SN - 0022-328X

IS - 23

ER -