Abstract
A new sterically demanding pentadentate thiolate-amine ligand py
t
BuN
2S
2–H
2 [
=
py
t
Bu
N
2
H
2
S
2
2
-
=
2
,
6
-bis
(
2
-mercapto-
3
,
5
-di-
tert
-butylphenylaminomethyl
)
pyridine
(
2
-
)
] and its zinc complexes were synthesized.Template condensation of bis(2-mercapto-3,5-di-
tert-butylaniline)zinc [Zn(
t
Bu
2ma)
2] and pyridine-2,6-dicarbaldehyde followed by
in situ reduction with NaBH
4 leads to the formation of [Zn(py
t
BuN
2H
2S
2)].Demetallation of the zinc complex [Zn(py
t
BuN
2H
2S
2)] under acidic conditions leads to the formation of the desired dithiolate py
t
BuN
2H
2S
2–H
2 ligand.
In quest of complexes having [MN
3S
2] cores in the monomeric form and
trans-thiolate donor atoms, the new pentadentate thiolate amine py
t
BuN
2H
2S
2–H
2 [
=
py
t
Bu
N
2
H
2
S
2
2
-
=
2
,
6
-bis
(
2
-mercapto-
3
,
5
-di-
tert
-butylphenylaminomethyl
)
pyridine
(
2
-
)
] has been synthesized.The template condensation reaction of bis(2-mercapto-3,5-di-
tert-butylaniline)zinc (II)[Zn(
t
Bu
2ma)
2] and pyridine-2,6-dicarbaldehyde in methanol at 40
°C leads to the formation of imine zinc complex [Zn(py
t
BuN
2S
2)] (
7), which is very unstable and decomposes to give thiazole
5. However, if the template condensation is followed by
in situ reduction with an excess of NaBH
4, the stable saturated amine complex [Zn(py
t
BuN
2H
2S
2)] (
8) is formed. Demetallation of zinc complex
8 under acidic conditions leads to the formation of the desired dithiolate py
t
BuN
2H
2S
2–H
2 ligand (
9).