Chemistry Reference
In-Depth Information
O
O
OH
O
OH
O
O
O
O
OH
O
OH
O
HN
O
NH
O
NH
O
NH
O
NH
HN
O
HN
O
HN
NH
OH
O
O
NH
O
O
HN
O
HN
O
O
O
HO
O
O
HO
OH
O
Ga
2
L
1
3
M
4
L
2
6
O
O
52
(= L
1
H
4
)
54
(= L
2
H
4
)
51
53
(Each edge corresponds to L
2
.)
Scheme 18 Cage networks with bis-catechol ligands and metal ions (
gray circles
)
R
2
R
2
R
2
R
2
R
2
N
N
M
N
N
N
R
1
O
OR
1
R
1
O
R
1
O
OR
1
a
: R
1
= (CH
2
)
2
OCH
3
, R
2
= H,
M = Pd(II)
: R
1
= CH
3
, R
2
= OCH
3
,
M = Zn(II)
b
R
1
O
OR
1
R
1
O
R
1
O
OR
1
N
N
N
M
N
N
R
2
R
2
R
2
R
2
R
2
55
56
M
2
L
4
(= L)
Scheme 19 Molecular capsules with ligands containing anthracene panels
give self-assembled M
2
L
4
molecular capsule 55a (Scheme
19
)[
104
]. This capsule
has a large cavity with a diameter of 10
˚
surrounded by large aromatic shells and
can encapsulate large molecules such as [2.2]paracyclophane, 1-methylpyrene, and
C
60
as revealed by NMR and mass spectroscopy. The similar M
2
L
4
capsule 55b was
also synthesized from ligand 56b and Zn(II) ions [
105
]. This complex is highly
emissive (
F
f
0.81) relative to the corresponding Ni(II) and Pd(II) complexes.
Michl et al. proposed prismatic 3D networks consisting of linear rods and star-
shaped connectors linked by Pt(II) metals at the corners (Scheme
20
)[
106
]. For
example, treatment of biphenyl rods and 1,3,5-tris(4-pyridylethynyl)phenyl caps
gave trigonal prism complex 57a [
107
]. MM calculation suggested that its frame-
work was slightly twisted from the regular trigonal prism to form a chiral structure.
The distance from the prism center to the central CH
2
moiety in the dppp moiety is
15.2
˚
. Complex 57b possesses three 9,10-diethynyltriptycene moieties at the rod
