Influence of the Growing Flexible Shell on the Molecular Behavior of Hybrid Dendrimers

A versatile approach to the synthesis of hybrid dendrimers composed of a rigid aromatic core and a flexible carbosilane shell is proposed. For this, carbosilane monodendrons of the first, second, and third generations were linked to a Muellen-type polyphenylene dendrimer via the copper-catalyzed azide–alkyne cycloaddition reaction. A series of hybrid dendrimers with a fixed phenylene core size and various carbosilane peripheries were synthesized to clarify the influence of a growing flexible shell on thermal and rheological dendrimer properties. Small-angle X-ray scattering experiments and density functional theory calculations revealed that the dendrimers form a columnar phase with hexagonal (G1, G2) and orthorhombic (G3) types of packing.