Chemistry Reference
In-Depth Information
12.2 DENDRIMERS CONTAINING SINGLE CHROMOPHORES AS
NANOSCALE REPORTERS
12.2.1 Introduction
By monitoring their fluorescence, single chromophores can serve as sensitive
reporters of the local environment [27-32]. In the same way, dendrimers containing
single chromophores in the core or at the rim can also serve as sensitive reporters of
motion as well as polarity changes of their immediate surroundings. The covalent
incorporation of chromophores into the center leads to macromolecular architectures
of well-defined sizes (see Figure 12.2 for an example) [33]. By adjusting the
polyphenylene shell, nanoemitters of well-defined size can be obtained. Figure 12.2
depicts the transition from a molecular perylene diimide (PDI) emitter
1
to a third-
generation dendrimer with a PDI in the center
4
. An increase of the number of
FIGURE 12.2
2D structures of themolecular PDI emitter. The transition from the emitter
1
to
the nanoscopic dendritic emitters
2
with four branches of first generation,
3
with second
generation, and
4
with third-generation polyphenylene dendrimer branches is shown.
4a
shows
the 2D structure of a third-generation dendrimer with PDI in the center and
4b
represents a
visualization of the 3D structure of the same molecule.
