Liquid-crystalline perylene tetracarboxylic bisimide derivatives bearing cyclotetrasiloxane moieties

Liquid-crystalline perylene tetracarboxylic bisimide derivatives bearing heptamethylcyclotetrasiloxane moieties have been synthesized. Compound 2 bearing four heptamethylcyclotetrasiloxane moieties exhibits a rectangular columnar phase at room temperature. In the columnar phase, the cyclotetrasiloxane rings interdigitate into neighbouring columns and their interaction promotes the formation of the columnar mesomorphic structure. A time-of-flight measurement reveals that the electron mobility in the columnar phase of compound 2 is on the order of 10−2 cm2 V−1 s−1 at room temperature. Compound 2 is soluble in various organic solvents except for alcohol.