Chemistry Reference
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Fig. 3.37
X-ray crystal structure of
a
the trigonal-planar branch constructed from three Q[8]
molecules linked by a Na
+
+
cation and the detailed coordination of Q[8] to the Na
cation;
−
b
the six-Q[8]-membered ring riming of six [In(H
2
O)
2
Cl
4
]
anions at both portals;
c
top
view;
+
d
an overall view of the superimposed 2D Q[8]/Na
networks;
e
an isolated tubular channel
constructed from the six-Q[8]-membered rings and the rimmed [In(H
2
O)
2
Cl
4
]
−
anions. Adapted
from Ref. [
59
] with permission from The Royal Society of Chemistry
stacking of the Q[8]/Sr
2
+
networks repeatedly overlay upon one another in exact
order, creating tubular channels (Fig.
3.38
c-d).
Above, we mentioned the first novel 3D framework in which a Hyq molecule
is included in the cavity of a Q[7] molecule. This inclusion results in the coor-
dination of rubidium cations to the portal carbonyl oxygens of the Q[7] hosts.
Formation of a Q[7]-based framework is a consequence of the Q[7]-Rb
+
coordina-
tion [
55
]. Herein, we introduce a novel 3D framework generated by crystallization
of a ternary mixture of Q[8], CsCl, and Hyb [
60
]. The crystal structure shows that
there are two different inclusion complexes of (Hyb)
2
@Q[8] in the unit consisting
of four Q[8] molecules (Fig.
3.39
a): two parallel Hyb molecules almost vertically
insert into the cavity of the host Q[8] (Fig.
3.39
b), and two parallel Hyb molecules
incline in the cavity of the host Q[8]. In addition, both Hyb molecules coordinate
with cesium cations in the (Hyb)
2
@Q[8] complex (Fig.
3.39
c). Coordination of
the hydroxyl oxygen atom (O(17)) with the two included Hyb molecules induces
further coordination of the Cs1 cation to the portal carbonyl oxygen atoms (O(12)
and O(13)) of the host Q[8]. Moreover, there are two
b
complexes and two
c
complexes in the unit of four Q[8]molecules; they are connected by a unit of two
cesium cations (Fig.
3.39
d). Each cesium Cs1 coordinates directly to three Q[8]
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