(Fig. 10a) changes the size of the 3D molecule with high precision. This affects the
transport through porous materials. More importantly, the ion conductivity of such
salts now becomes photoswitchable. Another case is the related structure with a
perylenediimide core. Figure 10b illustrates that the space inside the dendrimer is
suitable for the uptake of guest molecules. After forming the cis-isomer, the guest
molecule is firmly entrapped and can only be released upon back-isomerization to
the trans-isomer. It is tempting to think of such PPDs as vehicles carrying a payload
of drugs, but now with the additional advantage of controlled uptake and release.
N
N
O
O
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O O
O O
N
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N N
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=
B
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=
A
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B
N
B
Fig. 9 PPDs with inserted azobenzene units and different cores: (a) perylendiimide, (b) borate
Fig. 8 Dendrimer for light-emitting diodes. Design of a PPD incorporating triphenylamines,
triphenylene, and pyrene in defined positions
Structure Formation of Polymeric Building Blocks: Complex Polymer Architectures
129