Liquid crystalline and charge transport properties of novel non-peripherally octasubstituted perfluoroalkylated phthalocyanines

Abstract

Two new perfluoroalkylated phthalocyanine derivatives were synthesised and characterised in order to investigate the effects of the fluorophobic/fluorophilic interactions on their mesophase and electronic properties. Both compounds exhibit columnar mesomorphism and the thermal stability of the columnar phase is enhanced by over 20 °C as the number of fluorinated carbons increases, probably due to the nano-segregation between the fluorinated and hydrocarbon moieties in the chains. Also a strong tendency towards spontaneous homeotropic alignment was observed. Time of Flight (ToF) measurements were carried out to reveal the mobility characteristics and the ambipolar mobility was measured in the order of 10⁻¹ to 10⁻² cm² V⁻¹ s⁻¹ for the mesophases.