Artificial antennae

Metal dendrimers containing photoactive units exhibit very interesting properties, both from a fundamental and applicative viewpoint. For example, well-designed photoactive dendrimers can play the role of artificial antennae in supra-molecular structures devoted to solar energy conversion [37,47]. Photophysical... 

Finally, energy migration, i.e. excitation energy hopping, in polymers, artificial antenna systems, photo synthetic units, etc. can be investigated by fluorescence polarization (see Chapter 9). 

Figure 20. Schema ic representation of an artificial antenna for light harvesting.

It should be mentioned, however, that the three basic steps toward the preparation of artificial antennae, that is, (1) selection of building blocks, (2) connections between selected building blocks, and (3) synthetic strategies, are also strictly correlated to each other. In other words, the right connections (and synthetic procedure) have to be designed for the given building blocks. 

Balaban TS. Tailoring porphyrins and chlorins for self-assembly in biomimetic artificial antenna systems. Acc Chem Res 2005 38 612-23. 

The aim of this article is to discuss the basic requirements that an antenna system has to fulfill and to summarize some examples of the various artificial antennas reported in the literature. For the sake of comparison, brief comments on natural antennas are also presented. 

For an artificial antenna to be effective, it should contain as much chromophore as possible. This point immediately calls for the development of suitable substrates to which the chromophores should be linked and/or of properly designed synthetic... 

The ideal sequence of choices which has usually been followed for the construction of artificial antennas up to now is shown in Figure 4. Flowever, this sequence could be revolutionized if quite different approaches for the assembly of chromo-phores (e.g., self-assembly) should emerge. 

Because Nature elected porphyrin derivatives as components of the natural antennas, it cannot be surprising that many artificial antennas are based on these chromophores. This represents surely the largest class of artificial antennas studied. Even for this class, we discuss just a few representative examples [28]. 

In the very last few years, a molecular architecture which has received more and more attention in view of the construction of artificial antennas is that typical of dendrimers. Dendrimers are highly branched molecules which resemble the shape of... 

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