Figure-of-eight Shaped Metal-free Amide-containing Schiff-base Macrocycles and Two Dicobalt(III) Amide Complexes

Abstract

Two 36-membered (2+2) Schiff-base macrocycles have been prepared and characterised without the use of template ions or high dilution techniques. Rather, intramolecular hydrogen-bonding and π-π interactions promote the isolation of these 'figure-of-eight' products in good yields. Two cobalt(III) complexes of the 18-membered (1+1) Schiff-base macrocycles are formed when cobalt(II) is used as a template. The structures of one 'figure-of-eight' metal-free (2+2) macrocycle and of one dicobalt(III) complex of a (1+1) macrocycle, in which the cobalt centres are octahedral, are presented. [H4L1tBu]2: C70H70N8O9, space group P-1, a = 7.747(1), b = 17.106(3), c = 23.662(4) Å, α = 104.83(3), β = 95.86(3), γ = 97.80(3)°, U =2972.4(8) Å3, Z = 2, Dc = 1.30 g cm-3, T = 100K, 554 parameters, R1 = 0.072 [for 4137 reflections having F>4[(F)], wR2 = 0.191 and goodness of fit 0.97 (for all 8343 independent F2 data). [Co2(L1tBu)(OAc)2(pyridine)] 1.5DMF 0.5MeCN, C47.5H49N7O9.5Co2, space group P2(1)/n, a = 13.067(2), b = 26.071(4), c = 14.023(3) Å, β= 93.02(1)°, U = 4770.6(15) Å3, Z = 4, Dc = 138 g cm-3, T = 168K, 622 parameters, R1 = 0.075 [for 5233 reflections having F>4[(F)] wR2 = 0.133 and goodness of fit 1.08 (for all 8512 independent F2 data).