Lithium, sodium and potassium picolyl complexes: syntheses, structures and bonding

Research output: Contribution to journalArticle

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Abstract

Synthetically important for introducing a picolyl scaffold into a molecular construction, alkali metallated picoline (methylpyridine) complexes are also interesting in their own right for the diversity of their ligand-metal bonding possibilities. Here the syntheses of seven new such complexes are reported: namely three 4-picoline derivatives 4-picLi·Me6TREN, 1, 4-picNa·Me6TREN, 2, and [4-picK·2(4-picH)], 3; and four 2-picoline derivatives, 2-picLi·Me6TREN, 4, 2-picLi·PMDETA, 4′, 2-picNa·Me6TREN, 5, and [2-picK·PMDETA]2, 6′ [where pic = NC5H4(CH2); Me6TREN = tris(N,N-dimethyl-2-aminoethyl)amine, (Me2NCH2CH2)3N; PMDETA = N,N,N′,N′′,N′′-pentamethyldiethylenetriamine, (Me2NCH2CH2)2NMe]. X-ray crystallographic studies establish that the lighter alkali metal complexes 1, 2, 4′ and 5 adopt monomeric structures in contrast to the polymeric and dimeric arrangements adopted by potassium complexes 3 and 6′ respectively. All complexes have also been characterized by solution NMR spectroscopy (1H, 13C, and where relevant 7Li). This study represents the first example of sodium and potassium picolyl complexes to be isolated and characterized. DOSY (Diffusion-Ordered Spectroscopy) experiments performed on 4 and 4′ suggest both compounds retain their monomeric constitutions in C6D6solution. Discussion focuses on the influence of the metal and neutral donor molecule on the structures and the nature of the ligand-metal (enamido versus aza-allylic) interactions.

LanguageEnglish
Pages14265-14274
Number of pages10
JournalDalton Transactions
Volume43
Issue number38
Early online date22 Apr 2014
DOIs
Publication statusPublished - 14 Oct 2014

Fingerprint

Lithium
Potassium
Sodium
Picolines
Metals
Ligands
Alkali Metals
Derivatives
Coordination Complexes
Alkalies
Scaffolds
Nuclear magnetic resonance spectroscopy
Amines
tris(2-(dimethylamino)ethyl)amine
Spectroscopy
X rays
Molecules
Experiments

Keywords

  • picolyl scaffold
  • molecular construction
  • ligand–metal bonding

Cite this

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title = "Lithium, sodium and potassium picolyl complexes: syntheses, structures and bonding",
abstract = "Synthetically important for introducing a picolyl scaffold into a molecular construction, alkali metallated picoline (methylpyridine) complexes are also interesting in their own right for the diversity of their ligand-metal bonding possibilities. Here the syntheses of seven new such complexes are reported: namely three 4-picoline derivatives 4-picLi·Me6TREN, 1, 4-picNa·Me6TREN, 2, and [4-picK·2(4-picH)]∞, 3; and four 2-picoline derivatives, 2-picLi·Me6TREN, 4, 2-picLi·PMDETA, 4′, 2-picNa·Me6TREN, 5, and [2-picK·PMDETA]2, 6′ [where pic = NC5H4(CH2); Me6TREN = tris(N,N-dimethyl-2-aminoethyl)amine, (Me2NCH2CH2)3N; PMDETA = N,N,N′,N′′,N′′-pentamethyldiethylenetriamine, (Me2NCH2CH2)2NMe]. X-ray crystallographic studies establish that the lighter alkali metal complexes 1, 2, 4′ and 5 adopt monomeric structures in contrast to the polymeric and dimeric arrangements adopted by potassium complexes 3 and 6′ respectively. All complexes have also been characterized by solution NMR spectroscopy (1H, 13C, and where relevant 7Li). This study represents the first example of sodium and potassium picolyl complexes to be isolated and characterized. DOSY (Diffusion-Ordered Spectroscopy) experiments performed on 4 and 4′ suggest both compounds retain their monomeric constitutions in C6D6solution. Discussion focuses on the influence of the metal and neutral donor molecule on the structures and the nature of the ligand-metal (enamido versus aza-allylic) interactions.",
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Lithium, sodium and potassium picolyl complexes : syntheses, structures and bonding. / Kennedy, Alan R.; Mulvey, Robert E.; Urquhart, Robert I.; Robertson, Stuart D.

In: Dalton Transactions, Vol. 43, No. 38, 14.10.2014, p. 14265-14274.

Research output: Contribution to journalArticle

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T1 - Lithium, sodium and potassium picolyl complexes

T2 - Dalton Transactions

AU - Kennedy, Alan R.

AU - Mulvey, Robert E.

AU - Urquhart, Robert I.

AU - Robertson, Stuart D.

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N2 - Synthetically important for introducing a picolyl scaffold into a molecular construction, alkali metallated picoline (methylpyridine) complexes are also interesting in their own right for the diversity of their ligand-metal bonding possibilities. Here the syntheses of seven new such complexes are reported: namely three 4-picoline derivatives 4-picLi·Me6TREN, 1, 4-picNa·Me6TREN, 2, and [4-picK·2(4-picH)]∞, 3; and four 2-picoline derivatives, 2-picLi·Me6TREN, 4, 2-picLi·PMDETA, 4′, 2-picNa·Me6TREN, 5, and [2-picK·PMDETA]2, 6′ [where pic = NC5H4(CH2); Me6TREN = tris(N,N-dimethyl-2-aminoethyl)amine, (Me2NCH2CH2)3N; PMDETA = N,N,N′,N′′,N′′-pentamethyldiethylenetriamine, (Me2NCH2CH2)2NMe]. X-ray crystallographic studies establish that the lighter alkali metal complexes 1, 2, 4′ and 5 adopt monomeric structures in contrast to the polymeric and dimeric arrangements adopted by potassium complexes 3 and 6′ respectively. All complexes have also been characterized by solution NMR spectroscopy (1H, 13C, and where relevant 7Li). This study represents the first example of sodium and potassium picolyl complexes to be isolated and characterized. DOSY (Diffusion-Ordered Spectroscopy) experiments performed on 4 and 4′ suggest both compounds retain their monomeric constitutions in C6D6solution. Discussion focuses on the influence of the metal and neutral donor molecule on the structures and the nature of the ligand-metal (enamido versus aza-allylic) interactions.

AB - Synthetically important for introducing a picolyl scaffold into a molecular construction, alkali metallated picoline (methylpyridine) complexes are also interesting in their own right for the diversity of their ligand-metal bonding possibilities. Here the syntheses of seven new such complexes are reported: namely three 4-picoline derivatives 4-picLi·Me6TREN, 1, 4-picNa·Me6TREN, 2, and [4-picK·2(4-picH)]∞, 3; and four 2-picoline derivatives, 2-picLi·Me6TREN, 4, 2-picLi·PMDETA, 4′, 2-picNa·Me6TREN, 5, and [2-picK·PMDETA]2, 6′ [where pic = NC5H4(CH2); Me6TREN = tris(N,N-dimethyl-2-aminoethyl)amine, (Me2NCH2CH2)3N; PMDETA = N,N,N′,N′′,N′′-pentamethyldiethylenetriamine, (Me2NCH2CH2)2NMe]. X-ray crystallographic studies establish that the lighter alkali metal complexes 1, 2, 4′ and 5 adopt monomeric structures in contrast to the polymeric and dimeric arrangements adopted by potassium complexes 3 and 6′ respectively. All complexes have also been characterized by solution NMR spectroscopy (1H, 13C, and where relevant 7Li). This study represents the first example of sodium and potassium picolyl complexes to be isolated and characterized. DOSY (Diffusion-Ordered Spectroscopy) experiments performed on 4 and 4′ suggest both compounds retain their monomeric constitutions in C6D6solution. Discussion focuses on the influence of the metal and neutral donor molecule on the structures and the nature of the ligand-metal (enamido versus aza-allylic) interactions.

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