Abstract
The very different multi-step routes to the closely related pair of diformyl-carbazole head units, 1,8-diformyl-3,6-di-
tert
-butyl-9
H
-carbazole (
1tBu
) and 1,8-diformyl-9
H
-carbazole (
1H
), are detailed and compared. The first examples of Schiff base macrocycles derived from diformyl-carbazole head units are reported. Specifically, the direct cyclisation of
1tBu
or
1H
with diethylenetriamine gives the two metal-free [1 + 1] Schiff base macrocycles H
LH
and H
LtBu
in high yields. Four carbazole-based macrocyclic complexes, [Cu
II
L
(OH
2
)]OAc and [Ni
II
L
]OAc, where
L
=
LH
or
LtBu
, were accessed either by metallation of these macrocycles, or by metal templated reaction of the macrocycle components. [Cu
II
LtBu
(OH
2
)]OAc·0.5(Ether) and [Ni
LH
]OAc·EtOH, were structurally characterised, confirming the nickel(
ii
) complexes are square planar (both show diamagnetic NMR spectra) and that the copper(
ii
) complexes are square pyramidal with a water molecule bound in the axial site. Like porphyrins, both of these N
4
-donor macrocycles, which differ only in the R group present at the 3 and 6 positions (H or
t
Bu), impose a strong ligand field.