Synthesis, Structures, and Magnetic Properties of N ‐Trialkylsilyl‐8‐amidoquinoline Complexes of Chromium, Manganese, Iron, and Cobalt as well as of Wheel‐Like Hexanuclear Iron(II) and Manganese(II) Bis(8‐amidoquinoline)

The transamination of 8‐( tert ‐butyldimethylsilylamino)quinoline with (thf) 2 Cr[N(SiMe 3 ) 2 ] 2 yields monomeric bis[8‐( tert ‐butyldimethylsilylamido)quinoline]chromium(II) ( 1 ). Similar reactions of M[N(SiMe 3 ) 2 ] 2 (M = Mn, Fe, Co) with 8‐(trialkylsilylamino)quinoline lead to the formation of monomeric bis[8‐(trialkylsilylamido)quinoline]metal(II) [M = Mn, SiR 3 = SiMe 2 t Bu ( 2a ), Si i Pr 3 ( 2b ); M = Fe, SiR 3 = SiMe 2 t Bu ( 3a ),Si i Pr 3 ( 3b ); M = Co, SiR 3 = SiMe 2 t Bu ( 4a ), Si i Pr 3 ( 4b )]. The transamination of 8‐aminoquinoline with M[N(SiMe 3 ) 2 ] 2 (M = Mn, Fe, Co) allows the isolation of the heteroleptic 1:1 and homoleptic 2:1 products. The 1:1 complexes bis[8‐amidoquinoline metal(II)bis(trimethylsilyl)amide] [M = Mn ( 5 ), Fe ( 6 ), Co ( 7 )] are dimeric with bridging 8‐amidoquinoline moieties. The 2:1 complexes of Mn and Fe, bis(8‐amidoquinoline)manganese(II) ( 8 ) and bis(8‐amidoquinoline)iron(II) ( 9 ), form hexamers with wheel‐like molecular structures consisting of metal‐centered nitrogen octahedra interconnected by common N ··· N edges. The cobalt complex, bis(8‐amidoquinoline)cobalt(II) ( 10 ), precipitates as a microcrystalline powder. Investigations of the magnetic properties by DFT corroborate the experimental data for the Mn derivative 8 , where an antiferomagnetic coupling is observed. By contrast, calculations on the Fe 6 ‐wheel 9 yield very close‐lying ferromagnetically and antiferromagnetically coupled states.