Fabrication of porous organic polymers in the form of powder, soluble in organic solvents and nanoparticles: a unique platform for gas adsorption and efficient chemosensing

Abstract

Conjugated porous organic polymers based on a novel core of tetraphenyl-5,5-dioctylcyclopentadiene (TPDC) have been fabricated in the form of powder (P1), soluble in common organic solvents (P2) as well as aqueous dispersion of nanoparticles (P3). Fine tuning of the conditions of polycondensation reactions involving tetrakis(4-bromophenyl)-5,5-dioctylcyclopentadiene and diethynylbenzene leads to the formation of TPDC based polymers in three different forms. P1, P2 and P3 possess high thermal stability (up to 375 °C) and are porous in nature. The Brunauer–Emmett–Teller (BET) surface area and total pore volume of P1 were estimated to be 405 m² g⁻¹ and 0.68 cm³ g⁻¹ respectively. Solid P1 was explored for hydrogen and carbon dioxide adsorption. Solution of P2 and aqueous dispersion of P3 exhibit strong cyan fluorescence and are applied for the sensing of nitroaromatics. Steady state and time resolved fluorescence measurements reveal the underlying photophysics of amplified fluorescence quenching of P2 and P3 by nitroaromatics. Porosity, gas adsorption, as well as solubility, strong fluorescence and sensing capabilities establish TPDC based porous polymers as new multifunctional materials and can find broad applications in sensing and optical devices.