Chemistry Reference
In-Depth Information
Fig. 3.31
X-ray crystal structure of Q[7]/UO
2
2
+
-based 2D coordination network
a
side view;
b
top view;
c
coordination of a Q[7] molecule with four UO
2
2
+
cations;
d
the UO
2
2
+
/SO
4
2
−
unit
found in the direction shown in Fig.
3.33
e; the network consists of fused seven-
membered bracelets in which each Q[7] “bead” is linked by directly coordinated
rubidium ions (Fig.
3.33
f). The size of the bracelet is partly dictated by the size of
each Q[7] bead, which has a diameter of ~13 Å. The seven-membered bracelets
have a diameter of around 10.43 Å (Fig.
3.33
f). Thus, the seven-membered brace-
let rings lead to the formation of channel structures with different sizes and shapes
in the compound. The channels are filled with water molecules that form a com-
plicated hydrogen bonding network among themselves, as well as with the water
molecules coordinated to the metal centers [
55
].
3.5 Induced Coordination Polymers of Cucurbit[8]uril
with Metal Ions
The coordination of metal ions to Q[
n
]s and their coordination polymers in the
presence of inorganic structure inducers have been extensively investigated in our
laboratory. In particular, we introduced certain transition metal ions into metal-
Q[
n
] systems in an HCl solution to prepare various polydimensional coordination
Search WWH ::
Custom Search