Chemistry Reference
In-Depth Information
Figure 1.5. View of the Mobius stabilized annulene. Crystallographic data from
Ajami, 2003. The tetradehydrodianthracene and twisted structures are shown left
and right of the figure, respectively. C and H are represented by black and light
grey balls, respectively.
of combinations. Including pentagons leads to the assembling of crucial molecules
such as TTF, thiophenes and transitionmetal dithiolates, as well as TTF-derivatives,
FA, DIP, C
60
,
p
-NPNN,
p
-NC
CNSSN, etc.
Once topologically classified, the molecules can be classified in families. Based
on a core molecule such as TTF, a myriad of molecules can be synthesized. We
can thus schematize a molecule in three parts: core, functional groups and spac-
ers. For EDT-TTF-CN, TTF is the core and EDT and CN the functional groups.
Perylene is the core of molecules such as PTCDA, PTCDI, etc. A spacer sep-
arates two parts of a molecule. A carbon-carbon bond in biphenyl is a simple
example of a spacer, DTEDT is a further example, but in a large molecule a
spacer can be a full TTF molecule. The chemical manipulation of molecules is
a key property of MOMs. Think of inorganic materials where the building blocks,
atoms, cannot be chemically designed. The intense research on chemical syn-
thesis has led to the preparation of extremely complex molecules. Adding more
and more cores, functional groups and spacers leads to very large molecules with
open (dendrimers) or closed (macrocycles) structures, which will be discussed in
Section 2.5.
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C
6
F
4
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