Zur Reaktion von Makrozyklen mit Lanthanoiden. II. Die Strukturen von [K(thf)3]2[(C22H28N4)2Sm2] · 4THF und [(C22H22N4)Co] · DME

On the Reaction of Macrocycles with Lanthanoids. II. The Crystal Structures of K(thf)₃]₂(C₂₂H₂₈N₄)₂Sm₂] · 4 THF and (C₂₂H₂₂N₄)Co] · DME In a complicated redox reaction (TMTAA)K₂] and SmI₂(thf)₂] form the polynuclear metal complex K(thf)₃]₂(TMTAT)₂Sm₂]. This complex crystallizes with four molecules THF per formula unit and its structure was determined by single crystal X-ray investigation (spacegroup P2₁/c (No. 14), z = 4, a = 998.0(2) pm, = b = 2618.3(6) pm, c = 1619.4(3) pm, β = 96.52(2)°). In the dimeric unit (TMTAT)₂Sm₂]^2? the Sm³⁺ ions are bonded to the four N atoms of the macrocyclic ligand and one C₆H₄ ring of the second ligand is attached η⁶ like to one metal ion. Additionally two K(thf)₃]⁺ fragments are bonded to this central unit, and therefor coordination number seven results for the K⁺ ion. TMTAA]^2? is not reduced by Cp₂Co] in a similar reaction. The monomeric paramagnetic complex (TMTAA)Co] (μ_eff = 2,76 μ_B) is formed instead. The structure reveils a square planar coordination of the Co atom by the four N atoms of the TMTAA ligand (spacegroup C2/c (No. 15), z = 4, a = 1945.1(4) pm, b = 1165.6(2) pm, c = 1144.7(2) pm, β = 116.38(1)°).