Chemistry Reference
In-Depth Information
7.3 HYBRID FR
ยด
CHET-NEWKOME DENDRIMERS WITH A
VIOLOGEN CORE
Our interest inviologen-containing dendrimers and the differences noted above on the
space-filling properties of Newkome and Fr
echet dendrons led us to synthesize a new
series of dendrimers containing a dendron of each kind covalently attached to the
viologen nucleus [34] (see Figure 7.7). The synthesis of these dendrimers relied
on procedures previously reported by our group. Briefly, we first monoquaternized
4,4
0
-bipyridinewith 6-bromohexanoic acid. The resulting intermediate still contains a
free nitrogen on the bipyridine nucleus to which Fr
echet dendrons (as bromides) can
be easily attached. Finally, the terminal carboxylic acid on the other end of the
molecule can be reacted with the amine Newkome dendrons, to give rise to the final
FIGURE 7.7
Structures of hybrid Frechet-Newkome dendrimers with a viologen core.
