Dye-based covalent organic networks

Abstract This contribution presents four dye-based CONs derived from the reaction of triformylphloroglucinol with thionin acetate ( RIO-43 ), safranin chloride ( RIO-51 ), phenosafranin ( RIO-47 ), and Bismarck brown Y ( RIO-55 ). These materials, called Covalent Organic Networks (CONs), are insoluble solids formed by organic lamellar stacked structures and present permanent porosity, light absorption across the whole visible spectrum, fluorescence, ion exchange capability, and ion and electron conductivity. Periodic DFT calculations carried out indicated that the bent nature of most of those building blocks affords conductive extended materials containing pores with the shape of three-petal flowers, with the anion positioned at the petals. The turbostratic disorder makes only the center of the flower-shaped pores accessible, decreasing the specific surface areas. The material that has a higher surface area is the one derived from thionin acetate ( RIO-43 ), such as the highest electrical conductivity (1.96 × 10 ^–5 S cm ⁻¹ ), followed by RIO-47 ( 1.12 × 10 ^–7 S cm ⁻¹ ), RIO-55 (1.58 × 10 ^–7 S cm ⁻¹ ) and RIO-51 (3.26 × 10 ^–7 S cm ⁻¹ ).