Dendrimers peripheral functionalization with

The first dendrimeric structures peripherally functionalized with a polyhedral borane were reported by Barth et al. in 1994. For that purpose, zero, first, second, and third generation of amino-terminated PAMAM startbust dendrimers were boronated by their reaction with Na(CH3)3NB,oH8NCO. After that, the boronated dendrimers reacted with the monoclonal antibody MoAb IB16-6, previously derivatized with A-succinimidyl 3-(2-pyridyldithio)propionate, to obtain stable immunoconjugates. 

The same ligand system was used in the allylic alkylation of allyl trifluoroacetate with sodium diethyl-2-methylmalonate showing a more or less constant conversion over 8 h (20 exchanged reactor volumes). This is in contrast to peripheral functionalized dendrimers (Section 4.4.2), which deactivated at longer reaction times. 

Dendrimer interior functional groups and cavities can retain guest molecules selectively, depending on the nature of the guest and the dendritic endoreceptors, the cavity size, the structure, and the chemical composition of the peripheric groups. Two main methods are known for the synthesis of metal nanoparticles inside dendrimers. The first method consists of the direct reduction of dendrimer-encapsulated metal ions (Scheme 9.4) the second method corresponds to the displacement of less-noble metal clusters with more noble elements [54]. 

The convergent synthesis of a range of aryl ester dendrimers with peripheral tetrathiafulvalene units was also reported (Devonport et al. 1998). The dendrimers acquire some amount of the cation-radical tetrathiafulvalene tips on reacting with iodine in solutions. Another promising material is polyphenylene dendrimers functionalized with benzophenone units. On being transformed into the potassium ketyl derivatives, the dendrimers bring forth intermolecular biradicals. These technically attractive species contain four-membered cycles that coordinatively combine two potassium cations... 

ECL investigations of dinuclear or polynuclear Ru(II) complexes have been recently performed with hope for developing more efficient electrochemiluminescent materials. Centrally or peripherally functionalized dendrimers with active RuL32 + chelate units can produce higher (up to four to five times) ECL intensities as compared to their monomeric RuL32 + precursors alone. It was also found that the ECL intensities of metallodendrimers become larger as the multiplicity of the involved Ru(II) units increases. Similar observations have been reported for binuclear Ru(II) complexes with weak interaction between both metallic centers.84-88 These results indicate that further studies in such direction may result in design of still more efficient ECL systems based on Ru(II) luminophores. 

Poly(propyleneamine) dendrimers of generations 1 and 4 (89) functionalized with azobenzene groups were investigated as hosts for eosin Y (eosin = 2, 4, 5, 7 -tetrabromofluorescein dianion) in DMF solution [159]. The peripheral azobenzene groups can be switched by light excitation from the E to the Z form. The fluorescent excited state of eosin is reductively quenehed by the tertiary amine units present in the dendrimer structure. This electron transfer quenching takes place with a static... 

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