Syntheses and structural studies of lithium complexes of 2-amino-6-methylpyridine

Lithiation of 2-amino-6-methylpyridine (C5H3NMeNH2) occurred smoothly in diethyl ether (OEt2) or hexane–N,N,N',N'-tetramethylethylenediamine (tmeda) affording [Li(C5H3NMeNH)(OEt2)0.5 ] 1 or [Li(C5H3NMeNH)(tmeda)] 2. These complexes are extremely moisture sensitive and rapidly yield [Li8(C5H3NMeNH)6(O)(OEt2)2] 3 and [Li8(C5H3NMeNH)6(O)(tmeda)2] 4 respectively, upon exposure to limited amounts of water. On treatment of 1 with dimethylsilicone, insertion of dimethylsilicone into the Li–N bond occurs affording [Li4(C5H3NMeNHSiMe2O)4] 5. All complexes were characterised by spectroscopic and X-ray crystallographic methods. Complexes 3 and 4 reveal octanuclear centrosymmetric structures with an octahedral oxygen centre bound by six lithium atoms, and in 4 a monodentate tmeda ligand is identified. Compound 5 is tetranuclear with an Li4O4 pseudo-cubane core with each of these lithium atoms involved in six-membered chelate rings comprised of N–C–N–Si–O atoms with the lithium bound to the terminal N and O heteroatoms.

Dalton Transactions

Dalton Transactions

2000

1477-9234

N/A

18

5