Geomimetic Hydrothermal Synthesis of Polyimide-Based Covalent Organic Frameworks

Abstract

Despite its abundance, water is not widely used as a medium for organic reactions. However, under geothermal conditions, water exhibits unique physicochemical properties, such as viscosity, dielectric constant, and ionic product become similar to those of common organic solvents. In this study, for the first time, we synthesized highly crystalline polyimide-based covalent organic frameworks (PICs) under geomimetic hydrothermal conditions. By exploiting triphenylene-2,3,6,7,10,11-hexacarboxylic acid in combination with various aromatic diamines, PICs with various pore dimensions and crystallinities were synthesized. XRD, FT-IR, and DFT calculations revealed that the solubility of the oligomeric intermediates under hydrothermal conditions affected the stacking structures of the crystalline PICs. Furthermore, the synthesized PIC demonstrate promising potential as an anode material in lithium-ion battery owing to its unique redox-active property and high surface area.