Chemistry Reference
In-Depth Information
Table 1.5.
Debye temperatures of selected MOMs
Material
D
[K]
Reference
(TMTTF)
2
BF
4
51
Coulon
et al
., 1982
(TMTTF)
2
PF
6
55
Coulon
et al
., 1982
(TMTTF)
2
ClO
4
59
Coulon
et al
., 1982
δ
-
p
-NPNN
66
Nakazawa
et al
., 1992
γ
-
p
-NPNN
89
Nakazawa
et al
., 1992
TTF-TCNQ
90
Coleman
et al
., 1973a
β
-
p
-NPNN
140
Nakazawa
et al
., 1992
TTF-TCNQ
160
Saito
et al
., 1999
(TMTSF)
2
ClO
4
213
Garoche
et al
., 1982
(MDT-TSF)(AuI
2
)
0
.
44
300
Kawamoto
et al
., 2002
N
O
O
H
H
H
H
O
O
N
N
N
C
C
H
(a)
O
O
(b)
(c)
(d)
Figure 1.8. Some representative supramolecular synthons.
intermolecular interactions in the context of crystal packing and in the utilization of
such understanding in the design of new solids with desired physical and chemical
properties
(Desiraju, 1989). The major challenge of crystal engineering is that a
crystal structure is in fact a compromise between different interactions of varying
weak strengths and spatial distributions. Hence considering only one type of inter-
action, even if it turns out to be the strongest, when predicting crystal structures
usually leads to erroneous results, because the contribution of the neglected weaker
interactions can dominate.
Interactions can be combined by a designed placement of functional groups in
the molecular skeleton to generate supramolecular synthons, which are defined as
structural units within supermolecules that can be formed and/or assembled by
known or conceivable synthetic operations involving intermolecular interactions
(Desiraju, 1995). In other words supramolecular synthons are spatial arrangements
of intermolecular interactions.
Figure 1.8 shows a few examples of representative supramolecular synthons.
Synthons are derived from designed combinations of interactions and in general
