The conformation of various polystyrene chains with first (G-1), second (G-2), and third generation (G-3) Fréchet-type dendrons at the repeat unit has been investigated with small-angle neutron scattering. The increased density of the attached dendrons leads to a systematically greater cross-sectional chain diameter D. Bulky, high generation dendrons force the polymer backbone out of its all-trans conformation. The measured statistical Kuhn segment length initially increases in proportion to the chain diameter and then to a greater degree due to steric overcrowding and the concomitantly higher bending rigidity. The introduction of charges further leads to chain expansion and the development of interchain correlations. High molecular weight (G-2) chains develop fully excluded-volume chain properties with a Flory exponent of v ) 0.57 and a critical exponent γ ) 0.86 which is related to the enhancement of chain configurations with widely separated chain ends.

indicated by the topography of the films shown in Figure 6 (1c and 2c). Studies by Raman spectroscopy and X-ray diffraction are in progress in our laboratory to investigate the effect of canalization and a possible one-pot intercalation on these systems. Work is in progress to assemble an electrochromic device using this material and to study its photoelectrochemical properties.

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The synthesis of styrene monomers 5(G-I ,2,3) with Frichet-type dendrons of the first. second and third generation, and their radically initiated polymerization to result in high molecular weight dendrimers 6(G-I .2,3) are reported. First light-scattering investigations using 6(G-2) show that this polymer is best described as a Gaussian chain.

The synthesis of dendronized acrylate and styrene monomers with Frechet-type as well as urethane-based dendrons ofthe first and second generation and their radically initiated polymerization to the high molecular weight dendrimers 6(G-1,2) and 8 a(G-2) is reported. The latter polymer carries four THP-protected hydroxy fhctions per repeat unit whose quantitative deprotection is also described.