Figure-of-eight shaped metal-free amide-containing Schiff-base macrocycles and two dicobalt(III) amide complexes

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 pi-pi 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. [H(4)L1tBu](2): C70H70N8O9, space group P-1, a = 7.747(1), b = 17.106(3), c = 23.662(4) Angstrom, alpha =104.83(3), beta = 95.86(3), gamma = 97.80(3)degrees, U = 2972.4(8) Angstrom (3), Z = 2, D-c =1.30 g cm(-3), T =100 K, 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 F-2 data). [Co-2(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) Angstrom, beta = 93.02(1)degrees, U = 4770.6(15) Angstrom (3), Z=4, D-c = 1.38 g cm(-3), T = 168 K, 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 F-2 data).