The synthesis and glass-forming properties of phthalocyanine-containing poly(aryl ether) dendrimers

The synthesis, structural characterisation and properties of a number of ph thalocyanine-containing dendrimers are described. Peripheral substitution o f phthalocyanine (Pc) with four poly(aryl ether) dendritic wedges (Ist, 2nd or 3rd generation) produces materials whose properties are dominated both by the columnar self-association of the Pc core and by the glass-forming ch aracter of the dendritic substituents. Asymmetric Pcs containing a single p oly(aryl ether) dendron display a columnar mesophase, the structure of whic h can be frozen into an anisotropic glass at room temperature. Placing the dendritic wedges at the axial sites of silicon phthalocyanine prohibits sel f-association and gives materials from which can be fabricated robust, isot ropic solid solutions of Pc with high glass transition temperatures. A sing le crystal X-ray diffraction analysis of one of these compounds illustrates the ability of the axial dendrons to prevent cofacial aggregation in the s olid state.