Highly Conjugated Imidazoline Porous Organic Polymer (POP) for Green Photocatalytic Degradation of Toxic Mustard Gas

Abstract

Effective detoxification of CWA Mustard Gas (HD) via selective partial oxidation is the most effective but challenging method because the overoxidized sulfone product is toxic and the choice of solvent system. All organic and heterogenous photoactive porous organic polymers are more environmentally friendly and sustainable. Imidazoline-based POP, a new material class, consists of electron-rich and electron-deficient units in donor−acceptor junction and has mild oxidizing power and ROS generation ability. In this current work, IPPOP-4, a new Imidazoline POP, was synthesized, characterized, and found to be photoactive. Towards detoxification of HD simulant 2-chloroethyl ethylsulfide (CEES), IPPOP-4 showed excellent performance with ultrafast kinetics of t1/2 = 4.7 min in O2 and t1/2 = 5.8 min in air atmosphere, respectively, in MeOH as a suitable solvent system. Experimental data was presented that validates the crucial stage of the catalytic process that results in a plausible mechanism in the different solvent systems. Additionally, the versatile photocatalytic oxidative nature of the IPPOP-4 was established from its competence in the sulfide oxidation and aromatic aldehyde oxidation reaction with wide substrate scope. Furthermore, recyclability of the photocatalyst (upto 10 cycles) validates the conceptual feasibility of the photocatalyst.