Monomerizing alkali-metal 3,5-dimethylbenzyl salts with tris(N, N -dimethyl-2-aminoethyl)amine (MeTREN): structural and bonding implications

David R. Armstrong, Matthew G. Davidson, Daniel Garcia-Vivo, Alan R. Kennedy, Robert E. Mulvey, Stuart D. Robertson

Research output: Contribution to journalArticle

25 Citations (Scopus)

Abstract

The series of alkali-metal (Li, Na, K) complexes of the substituted benzyl anion 3,5-dimethylbenzyl (MeCHCH ) derived from 1,3,5-trimethylbenzene (mesitylene) have been coerced into monomeric forms by supporting them with the tripodal tetradentate Lewis donor tris(N,N-dimethyl-2-aminoethyl)amine, [N(CH CHNMe), MeTREN]. Molecular structure analysis by X-ray crystallography establishes that the cation-anion interaction varies as a function of the alkali-metal, with the carbanion binding to lithium mainly in a σ fashion, to potassium mainly in a π fashion, with the interaction toward sodium being intermediate between these two extremes. This distinction is due to the heavier alkali-metal forcing and using the delocalization of negative charge into the aromatic ring to gain a higher coordination number in accordance with its size. MeTREN binds the metal in a η mode at all times. This coordination isomerism is shown by multinuclear NMR spectroscopy to also extend to the structures in solution and is further supported by density functional theory (DFT) calculations on model systems. A MeTREN stabilized benzyl potassium complex has been used to prepare a mixed-metal ate complex by a cocomplexation reaction with tBuZn, with the benzyl ligand acting as an unusual ditopic σ/π bridging ligand between the two metals, and with the small zinc atom relocalizing the negative charge back on to the lateral CH arm to give a complex best described as a contacted ion pair potassium zincate.
LanguageEnglish
Pages12023-12032
Number of pages10
JournalInorganic Chemistry
Volume52
Issue number20
DOIs
Publication statusPublished - 2 Oct 2013

Fingerprint

Alkali Metals
alkali metals
Amines
potassium
Potassium
amines
Salts
salts
Anions
Metals
metals
methylidyne
anions
Ligands
mesitylene
ligands
X ray crystallography
heavy metals
Metal complexes
Lithium

Keywords

  • alkali metal
  • ions
  • stabilized monomers

Cite this

@article{2185505009494b0faeeca207e0d358a0,
title = "Monomerizing alkali-metal 3,5-dimethylbenzyl salts with tris(N, N -dimethyl-2-aminoethyl)amine (MeTREN): structural and bonding implications",
abstract = "The series of alkali-metal (Li, Na, K) complexes of the substituted benzyl anion 3,5-dimethylbenzyl (MeCHCH ) derived from 1,3,5-trimethylbenzene (mesitylene) have been coerced into monomeric forms by supporting them with the tripodal tetradentate Lewis donor tris(N,N-dimethyl-2-aminoethyl)amine, [N(CH CHNMe), MeTREN]. Molecular structure analysis by X-ray crystallography establishes that the cation-anion interaction varies as a function of the alkali-metal, with the carbanion binding to lithium mainly in a σ fashion, to potassium mainly in a π fashion, with the interaction toward sodium being intermediate between these two extremes. This distinction is due to the heavier alkali-metal forcing and using the delocalization of negative charge into the aromatic ring to gain a higher coordination number in accordance with its size. MeTREN binds the metal in a η mode at all times. This coordination isomerism is shown by multinuclear NMR spectroscopy to also extend to the structures in solution and is further supported by density functional theory (DFT) calculations on model systems. A MeTREN stabilized benzyl potassium complex has been used to prepare a mixed-metal ate complex by a cocomplexation reaction with tBuZn, with the benzyl ligand acting as an unusual ditopic σ/π bridging ligand between the two metals, and with the small zinc atom relocalizing the negative charge back on to the lateral CH arm to give a complex best described as a contacted ion pair potassium zincate.",
keywords = "alkali metal, ions, stabilized monomers",
author = "Armstrong, {David R.} and Davidson, {Matthew G.} and Daniel Garcia-Vivo and Kennedy, {Alan R.} and Mulvey, {Robert E.} and Robertson, {Stuart D.}",
year = "2013",
month = "10",
day = "2",
doi = "10.1021/ic401777x",
language = "English",
volume = "52",
pages = "12023--12032",
journal = "Inorganic Chemistry",
issn = "0020-1669",
publisher = "American Chemical Society",
number = "20",

}

Monomerizing alkali-metal 3,5-dimethylbenzyl salts with tris(N, N -dimethyl-2-aminoethyl)amine (MeTREN) : structural and bonding implications. / Armstrong, David R.; Davidson, Matthew G.; Garcia-Vivo, Daniel; Kennedy, Alan R.; Mulvey, Robert E.; Robertson, Stuart D.

In: Inorganic Chemistry, Vol. 52, No. 20, 02.10.2013, p. 12023-12032.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Monomerizing alkali-metal 3,5-dimethylbenzyl salts with tris(N, N -dimethyl-2-aminoethyl)amine (MeTREN)

T2 - Inorganic Chemistry

AU - Armstrong, David R.

AU - Davidson, Matthew G.

AU - Garcia-Vivo, Daniel

AU - Kennedy, Alan R.

AU - Mulvey, Robert E.

AU - Robertson, Stuart D.

PY - 2013/10/2

Y1 - 2013/10/2

N2 - The series of alkali-metal (Li, Na, K) complexes of the substituted benzyl anion 3,5-dimethylbenzyl (MeCHCH ) derived from 1,3,5-trimethylbenzene (mesitylene) have been coerced into monomeric forms by supporting them with the tripodal tetradentate Lewis donor tris(N,N-dimethyl-2-aminoethyl)amine, [N(CH CHNMe), MeTREN]. Molecular structure analysis by X-ray crystallography establishes that the cation-anion interaction varies as a function of the alkali-metal, with the carbanion binding to lithium mainly in a σ fashion, to potassium mainly in a π fashion, with the interaction toward sodium being intermediate between these two extremes. This distinction is due to the heavier alkali-metal forcing and using the delocalization of negative charge into the aromatic ring to gain a higher coordination number in accordance with its size. MeTREN binds the metal in a η mode at all times. This coordination isomerism is shown by multinuclear NMR spectroscopy to also extend to the structures in solution and is further supported by density functional theory (DFT) calculations on model systems. A MeTREN stabilized benzyl potassium complex has been used to prepare a mixed-metal ate complex by a cocomplexation reaction with tBuZn, with the benzyl ligand acting as an unusual ditopic σ/π bridging ligand between the two metals, and with the small zinc atom relocalizing the negative charge back on to the lateral CH arm to give a complex best described as a contacted ion pair potassium zincate.

AB - The series of alkali-metal (Li, Na, K) complexes of the substituted benzyl anion 3,5-dimethylbenzyl (MeCHCH ) derived from 1,3,5-trimethylbenzene (mesitylene) have been coerced into monomeric forms by supporting them with the tripodal tetradentate Lewis donor tris(N,N-dimethyl-2-aminoethyl)amine, [N(CH CHNMe), MeTREN]. Molecular structure analysis by X-ray crystallography establishes that the cation-anion interaction varies as a function of the alkali-metal, with the carbanion binding to lithium mainly in a σ fashion, to potassium mainly in a π fashion, with the interaction toward sodium being intermediate between these two extremes. This distinction is due to the heavier alkali-metal forcing and using the delocalization of negative charge into the aromatic ring to gain a higher coordination number in accordance with its size. MeTREN binds the metal in a η mode at all times. This coordination isomerism is shown by multinuclear NMR spectroscopy to also extend to the structures in solution and is further supported by density functional theory (DFT) calculations on model systems. A MeTREN stabilized benzyl potassium complex has been used to prepare a mixed-metal ate complex by a cocomplexation reaction with tBuZn, with the benzyl ligand acting as an unusual ditopic σ/π bridging ligand between the two metals, and with the small zinc atom relocalizing the negative charge back on to the lateral CH arm to give a complex best described as a contacted ion pair potassium zincate.

KW - alkali metal

KW - ions

KW - stabilized monomers

UR - http://www.scopus.com/inward/record.url?scp=84886670706&partnerID=8YFLogxK

UR - http://pubs.acs.org/journal/inocaj

U2 - 10.1021/ic401777x

DO - 10.1021/ic401777x

M3 - Article

VL - 52

SP - 12023

EP - 12032

JO - Inorganic Chemistry

JF - Inorganic Chemistry

SN - 0020-1669

IS - 20

ER -