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. [H
4
L1tBu]
2
: C
70
H
70
N
8
O
9
, 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) å
3
, Z=2, D
c
=1.30 g cm
−3
, T=100K, 554 parameters, R1=0.072 [for 4137 reflections having F>4[(F)], wR
2
=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, C
47.5
H
49
N
7
O9.5Co
2
, 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) å
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 good ness of fit 1.08 (for all 8512 independent F
2
data).