Antiaromatic expanded porphyrin enables redox-tunable photoconductivity in columnar liquid crystals

Liquid crystals (LCs) based on π-conjugated building blocks are well-established platforms for engineering soft optoelectronic materials. However, the incorporation of antiaromatic frameworks-despite their potential to unlock new functional paradigms-remains highly challenging. Herein, we report an antiaromatic expanded porphyrin that upon heating and then cooling self-assembles into a highly ordered rectangular columnar mesophase (Col_r). The resulting supramolecular organization enables photoinduced charge transport in the LC state that is markedly enhanced compared to the amorphous precursor state. Reductive (n-type) and oxidative (p-type) chemical doping was found to generate stabilized open-shell radical species within the Col_r assemblies and further boost their photoconductivity. The findings reported here establish antiaromatic expanded porphyrins as promising platforms for the construction of redox-responsive semiconducting soft materials.