Chemistry Reference
In-Depth Information
Fig. 3.10 a - c The structures of the related three SQ[5]s (top view) used for the preparation of
3D frameworks; d the trigonal-planar branches constructed from 1,2,4-HMeQ[5]s and K
+
ions; e
schematic illustrating the identical dihedrals (70.53°) between any two K1 junction planes in the
trigonal-planar branch; f part of a single 3D framework incorporating multifused 10-membered
1,2,4-HMeQ[5] bracelets; g a single 10-membered 1,2,4-HMeQ[5] “bracelet”; h catenation of
two 10-membered 1,2,4-HMeQ[5] bracelets; i part of the overall structure showing the two multi-
catenated 3D frameworks, each composed of multifused 10-membered 1,2,4-HMeQ[5] bracelets
triangular manner such that the edges of three portals are drawn close together to
form the trigonal-planar branch, which also incorporates two symmetrically posi-
tioned water oxygens. A similar (but not identical) arrangement occurs with the
K1 end of each 1,2,4-HMeQ[5] molecule. The offset angles of the adjacent portals
in both trigonal-planar branches are all 62.37°, with the distances of K1 and K2
from the corresponding 1,2,4-HMeQ[5] portal coordination planes varying slightly
by 0.821 and 0.900 Å, respectively. The two nonequivalent “junctions” are thus
constructed around three K1 and three K2 cations in the trigonal-planar branches.
The K + ions in each K1 junction, as well as in each K2 junction, are positioned
at the vertices of an equilateral triangle, as shown in Fig. 3.10 d. The separation
between K1 cations is 4.135 Å, whereas that between K2 cations is 4.017 Å. The
Search WWH ::




Custom Search