3.1.4 Metal–Organic Gelators Based on Tripyridine
and Tridentate Ligands
2,2′:6′,2″-Terpyridine is a widely used tridentate ligand because it can form
well-defined chelate complexes. For example, divalent Cu
2+ may form pentacoordinated N 3 Cl 2 terpyridine complexes. Cametti, Haukka and co-workers prepared
two ligands 20 and 21 (Scheme 3.7) based on a terpyridine moiety decorated with a
perfluorinated C 8 F 17 tag [32]. Both of them are able to gelate a series of d-block
metal ions, such as Zn
2+ and Hg
2+ in the mixture of DMSO and water. All four
N
N
N
R 1
Pt
R 1
R 1
R 2
32 R 1 = H, R 2 =
33 R 1 = tBu, R 2 =
34 R 1 = H, R 2 =
35 R 1 = H, R 2 =
N
H
Boc
H
N
O
N
H
Boc
H
N
O
N
H
Boc
H
N
O
N
N
N
N
H
O
N
H
Boc
H
N
N
N
N
N
H
O
N N
N
H
N
O
OTf
-
N
N
N
Y
Cu
X X
24 X = Cl, Y = O
25 X = Cl, Y = S
26 X = Br, Y = O
N
N
N
R
Cu
X X
27 R = Oxazol-2-yl, X=Cl
28 R = Phenyl, X=Cl
29 R = H, X = Cl
N
N
O
N
30
N
N
N
O
NH
30'
N
N
N
N
HO
OH
22
Cu
Cl
Cl
N
N
N
NMe 2
Zn
Cl Cl
23
N
N
N
R
20 R=
21 R=
O CH 2 CH 2 CH 2 (CF 2 ) 7 CF 3
O CH 2 CH 2 CH 2 (CF 2 ) 7 CF 3
N
N
N
O
31
Scheme 3.7 Molecular structures of 20–35
72
3 Metal–Organic Gels