Chemistry Reference
In-Depth Information
Pd
12+
N
N
N
N
N
N
N
N
N
N
N
N
Pd
Pd
N
N
NH
2
N
Pd
N
N
NN
Pd
Pd
=
H
2
N
Pd
N
N
N
N
N
N
N
N
N
47
N
N
12 NO
3
-
Pd
46
Scheme 16 Cage network with pyridine ligands and Pd metals
N
6+
PEt
3
Pt
L
PEt
3
=
=
PEt
3
Pt
L
L
PEt
3
N
N
6 PF
4
C
48
49
50
Scheme 17 Prismatic cage networks with anthracene clips and pyridine ligands
donors afforded various polyhedral 3D cages [
100
]. In most cases the shape of 3D
architectures is predictable by the combination of donor and acceptor subunits
according to the design principle called “directional bonding approach” [
21
].
Raymond et al. proposed a molecular design based on bis-catechol ligands and
metal ions for the construction of 3D networks (Scheme
18
)[
101
]. Triple helicates
were synthesized from three ligands and two octahedral metals. For example,
complex 51 consists of Ga(III) metals and ligand 52 to form an M
2
L
4
network,
which has a helical structure rather than a regular prismatic structure [
102
].
Tetrahedral M
4
L
6
complex 53 was similarly constructed from ligand 54 with a
naphthalene core and Ga(III) or Fe(III) metals, where metals and ligands occupied
corners and edges of a tetrahedron, respectively [
103
]. These tetrahedral complexes
can encapsulate various chemical species such as tetraalkylammonium ions and
cationic Ru complexes. When the tetrahedral Ga
4
L
6
network encapsulated CpRu(
p
-
isopropyltoluene) cation, the signals due to the two isopropyl-methyl groups in the
guest molecule were observed nonequivalently in the
1
H NMR spectrum. This
diastereotopic environment results from the chiral tetrahedral framework.
Molecular capsules with large anthracene panels were designed by Yoshizawa
et al. Bisanthracene ligand 56a was treated with Pd(NO
3
)
2
in DMSO in a 2:1 ratio to
