Liquid crystalline 21,23-dithiaporphyrins

Meso-substituted 21,23-dithiaporhyrins were synthesized that self-assemble into columnar liquid crystalline phases. Furthermore, the porphyrins possess absorption profiles that span from 400 nm to 800 nm, undergo two reversible electrochemical redox reactions at approximately 465 and 670 mV vs. ferrocene/ferricenium and are electrochromic. Thin films of these dithiaporhyrins of approximately 60 nm thickness were formed by spin-casting methods from chloroform and were subjected to impedance spectroscopy. The pristine films showed very low conductivity at open circuit potentials (undoped); however, electrochemically p-doping resulted in stable films with four orders of magnitude higher conductivity.