Not Only Columns: High Hole Mobility in a Discotic Nematic Mesophase Formed by Metal‐Containing Porphyrin‐Core Dendrimers

We report a new family of multifunctional liquid-crystalline porphyrin-core dendrimers that have coumarin functional groups around the porphyrin core. Porphyrin metalation strongly affects the photophysical properties, and therefore Zn and Cu derivatives have also been prepared. All the synthesized dendrimers form a nematic discotic mesophase. Their high tendency for homeotropic alignment makes these dendrimers excellent candidates for device applications, owing to their easy processability, spontaneous alignment between electrodes, and self-healing of defects because of their dynamic nature. The charge mobility values of these materials are the highest ever reported for a nematic discotic phase. Moreover, these values are similar to the highest values reported for ordered columnar mesophases, and this shows that a supramolecular organization in columns is not necessary to achieve high charge mobility.
This work was supported by the MINECO, Spain, under the project CTQ2012-35692 and CTQ2015-70174, FEDER funding, and Aragón Government (Research Group E04). A.C. thanks MINECO for his PhD grant. A. G. is grateful for support from the ELIOTROPO project (PON03PE_00092_2). R. T. was supported by MIUR underthe PRIN 2012 JHFYMC project.