Heavier alkali metal complexes of the bulky alkyl ligand 2-(bis(trimethylsilyl)methyl)-6-methylpyridine: Crystal structures of [{6-Me(2 Pyr)}(Me3Si)2CNa(pmdta)] and [{6-Me(2-Pyr)}(Me3Si)2CK]∞

Reaction of the bulky pyridyl based ligand 6-Me(2-Pyr)(Me3Si)2CH with nBuM (M = Na, K) in the presence of the N donors pmdta (N,N′,N′,N″,N″ pentamethyldiethylenetriamine) and tmeda (N,N,N′,N′ tetramethylethylenediamine) resulted in the formation and crystallisation of the heavy alkali metal complexes, [{6-Me(2-Pyr)}(Me3Si)2CNa(pmdta)], 1, and [{6-Me(2-Pyr)}(Me3Si)2CK]∞, 2. Single crystal X-ray diffraction studies show the sodium complex, 1, to be monomeric with a six coordinate metal centre, while the unsolvated potassium complex, 2, is polymeric, involving repeating η3 1-aza-allyl and allylic interactions of the pyridyl moiety with the potassium cation.

Two heavier alkali metal complexes of the bulky alkyl ligand 6-Me(2-Pyr)(Me3Si)2CH have been synthesised and characterised by single crystal X-ray diffraction. Monomeric [{6-Me(2-Pyr)}(Me3Si)2CNa(pmdta)] has six coordinate Na bonded to the ligand in an η3 1-aza-allyl manner, while [{6-Me(2-Pyr)}(Me3Si)2CK]∞ is an unsolvated polymer displaying both η3 1-aza-allyl and allylic interactions.Figure optionsDownload as PowerPoint slide