Adding rubidium and cesium to the homologous series of alkali metal compounds of (Trimethylsilyl)methanides and 2,2,6,6-Tetramethylpiperidides

William Clegg, Jan Klett, Robert E. Mulvey, Luca Russo, Alan Kennedy

Research output: Contribution to journalArticle

10 Citations (Scopus)

Abstract

(Trimethylsilyl)methylrubidium [RbCH2SiMe3] (1) and (trimethylsilyl)methylcesium [CsCH2SiMe3] (2) were prepared by metathesis reactions of (trimethylsilyl)methyllithium [LiCH2SiMe3] with rubidium or cesium tert-butoxide in n-hexane. Both new compounds are pyrophoric powders which were characterised by NMR spectroscopy and elemental analyses. They can be used as deprotonating agents towards secondary amines such as 2,2,6,6-tetramethylpiperidine (TMPH). The resulting amides [RbTMP] (3) and [CsTMP] (4) form temperature-sensitive, n-hexane-insoluble orange solids. Treatment with the bidentate donor N,N,N',N'-tetramethylethylenediamine (TMEDA) produces the corresponding n-hexane-soluble complexes. The crystal structures of [(TMEDA)RbTMP] (3a) and [(TMEDA)CsTMP] (4a) were determined to be closely related to that of [(TMEDA)KTMP]. Thus they are dimers with frameworks that consist of four-membered MNMN rings (M = Rb, Cs or K, N = TMP). The versatility and stability observed should make these (trimethylsilyl)methyl and TMP compounds of rubidium (1, 3a) and cesium (2, 4a) valuable starting points for further exploration of the chemistry of these heavy alkali metals.

Original languageEnglish
Pages (from-to)2989-2994
Number of pages6
JournalEuropean Journal of Inorganic Chemistry
Volume2012
Issue number18
DOIs
Publication statusPublished - Jun 2012

Fingerprint

Trimethylsilyl Compounds
Alkali metal compounds
Rubidium
Cesium
Thymidine Monophosphate
Alkali Metals
Amides
Dimers
Powders
Nuclear magnetic resonance spectroscopy
Heavy metals
Amines
Crystal structure
N,N,N',N'-tetramethylethylenediamine
n-hexane

Keywords

  • alkali metals
  • N-donor ligands
  • metalation
  • cesium
  • carbanions
  • rubidium

Cite this

@article{9446766703ce40c8bcab95453ae2e9fd,
title = "Adding rubidium and cesium to the homologous series of alkali metal compounds of (Trimethylsilyl)methanides and 2,2,6,6-Tetramethylpiperidides",
abstract = "(Trimethylsilyl)methylrubidium [RbCH2SiMe3] (1) and (trimethylsilyl)methylcesium [CsCH2SiMe3] (2) were prepared by metathesis reactions of (trimethylsilyl)methyllithium [LiCH2SiMe3] with rubidium or cesium tert-butoxide in n-hexane. Both new compounds are pyrophoric powders which were characterised by NMR spectroscopy and elemental analyses. They can be used as deprotonating agents towards secondary amines such as 2,2,6,6-tetramethylpiperidine (TMPH). The resulting amides [RbTMP] (3) and [CsTMP] (4) form temperature-sensitive, n-hexane-insoluble orange solids. Treatment with the bidentate donor N,N,N',N'-tetramethylethylenediamine (TMEDA) produces the corresponding n-hexane-soluble complexes. The crystal structures of [(TMEDA)RbTMP] (3a) and [(TMEDA)CsTMP] (4a) were determined to be closely related to that of [(TMEDA)KTMP]. Thus they are dimers with frameworks that consist of four-membered MNMN rings (M = Rb, Cs or K, N = TMP). The versatility and stability observed should make these (trimethylsilyl)methyl and TMP compounds of rubidium (1, 3a) and cesium (2, 4a) valuable starting points for further exploration of the chemistry of these heavy alkali metals.",
keywords = "alkali metals, N-donor ligands , metalation, cesium, carbanions , rubidium",
author = "William Clegg and Jan Klett and Mulvey, {Robert E.} and Luca Russo and Alan Kennedy",
year = "2012",
month = "6",
doi = "10.1002/ejic.201200122",
language = "English",
volume = "2012",
pages = "2989--2994",
journal = "European Journal of Inorganic Chemistry",
issn = "1434-1948",
number = "18",

}

TY - JOUR

T1 - Adding rubidium and cesium to the homologous series of alkali metal compounds of (Trimethylsilyl)methanides and 2,2,6,6-Tetramethylpiperidides

AU - Clegg, William

AU - Klett, Jan

AU - Mulvey, Robert E.

AU - Russo, Luca

AU - Kennedy, Alan

PY - 2012/6

Y1 - 2012/6

N2 - (Trimethylsilyl)methylrubidium [RbCH2SiMe3] (1) and (trimethylsilyl)methylcesium [CsCH2SiMe3] (2) were prepared by metathesis reactions of (trimethylsilyl)methyllithium [LiCH2SiMe3] with rubidium or cesium tert-butoxide in n-hexane. Both new compounds are pyrophoric powders which were characterised by NMR spectroscopy and elemental analyses. They can be used as deprotonating agents towards secondary amines such as 2,2,6,6-tetramethylpiperidine (TMPH). The resulting amides [RbTMP] (3) and [CsTMP] (4) form temperature-sensitive, n-hexane-insoluble orange solids. Treatment with the bidentate donor N,N,N',N'-tetramethylethylenediamine (TMEDA) produces the corresponding n-hexane-soluble complexes. The crystal structures of [(TMEDA)RbTMP] (3a) and [(TMEDA)CsTMP] (4a) were determined to be closely related to that of [(TMEDA)KTMP]. Thus they are dimers with frameworks that consist of four-membered MNMN rings (M = Rb, Cs or K, N = TMP). The versatility and stability observed should make these (trimethylsilyl)methyl and TMP compounds of rubidium (1, 3a) and cesium (2, 4a) valuable starting points for further exploration of the chemistry of these heavy alkali metals.

AB - (Trimethylsilyl)methylrubidium [RbCH2SiMe3] (1) and (trimethylsilyl)methylcesium [CsCH2SiMe3] (2) were prepared by metathesis reactions of (trimethylsilyl)methyllithium [LiCH2SiMe3] with rubidium or cesium tert-butoxide in n-hexane. Both new compounds are pyrophoric powders which were characterised by NMR spectroscopy and elemental analyses. They can be used as deprotonating agents towards secondary amines such as 2,2,6,6-tetramethylpiperidine (TMPH). The resulting amides [RbTMP] (3) and [CsTMP] (4) form temperature-sensitive, n-hexane-insoluble orange solids. Treatment with the bidentate donor N,N,N',N'-tetramethylethylenediamine (TMEDA) produces the corresponding n-hexane-soluble complexes. The crystal structures of [(TMEDA)RbTMP] (3a) and [(TMEDA)CsTMP] (4a) were determined to be closely related to that of [(TMEDA)KTMP]. Thus they are dimers with frameworks that consist of four-membered MNMN rings (M = Rb, Cs or K, N = TMP). The versatility and stability observed should make these (trimethylsilyl)methyl and TMP compounds of rubidium (1, 3a) and cesium (2, 4a) valuable starting points for further exploration of the chemistry of these heavy alkali metals.

KW - alkali metals

KW - N-donor ligands

KW - metalation

KW - cesium

KW - carbanions

KW - rubidium

UR - http://www.scopus.com/inward/record.url?scp=84862164336&partnerID=8YFLogxK

U2 - 10.1002/ejic.201200122

DO - 10.1002/ejic.201200122

M3 - Article

VL - 2012

SP - 2989

EP - 2994

JO - European Journal of Inorganic Chemistry

JF - European Journal of Inorganic Chemistry

SN - 1434-1948

IS - 18

ER -