142 Advances in Polymer Science Editorial Board: A. Abe. A.-C ...

Dendrimers and Dendrimer-Polymer Hybrids 209
Scheme 12
In the first case the resulting polymer has two dendrons for every three phenylene
rings and in the second case there are two dendrons on every second phenylene
ring. The higher apparent MW of the polymers, measured by SEC, suggest
that the first polymer is easier to prepare than the denser substituted second
polymer [114].
Recently, Oikawa et al. succeeded in polymerizing a phenyl acetylene monomer
carrying stiff dendrons of generation 1 and generation 2 [115] (see
Scheme 12). The dendrimer is attached to every second carbon in the poly(acetylene)
backbone. The apparent MW of the polymers is quite high (>1·10 6 ) and
the polymer solubility increases with increasing dendrimer generation. The replacement
of tert-butyl groups by trimethylsilyl groups also improves solubilization.
The maximum in the visible light absorption spectrum of the polymers