Supra-Amphiphilic Porphyrin Based on Thermoresponsive Poly(N-Isopropylacrylamide-co-2-Acrylamido-2-Methylpropane Sulfonic Acid Sodium) Hydrogels: Synthesis, Characterization and Catalytic Applications

The present study aims to introduce a new catalytic system, namely, thermo-responsive amphiphilic manganese porphyrin-paired ionic co -polymeric hydrogel, poly(N-isopropylacrylamide- co -2-acrylamido-2-methylpropane sulfonic acid sodium)-Mn (III) meso tetra(N-methyl-4-pyridyl) porphine, briefly called p(NIPAM- co-Na AMPS)‐[Mn(TMPyP)]. Free-radical polymerization at ambient temperature was employed to construct this catalytic system. To prepare this temperature-sensitive catalyst, “smart” poly(N-isopropylacrylamide- co -NaAMPS) was axially grafted onto the metal centers of the Mn III composite. Dynamic light scattering was used to determine the temperature-responsiveness of the catalyst and the hydrodynamic radii of the constructed compounds. In order to identify the amounts of metals in prepared compound, atomic absorption spectroscopy (AAS) was utilized. The results indicated that p(NIPAM- co-Na AMPS)‐[Mn(TMPyP)] had the potential to efficiently catalyze olefin oxidation with high selectivity in the solid–liquid biphasic reaction system. Furthermore, the catalytic activities of styrene, α -methyl-styrene, cis -cyclooctene, indene oxidation by the reaction-controlled phase transfer catalyst system were compared in the presence of hydrogen peroxide (H 2 O 2 ) and tert -Butyl hydroperoxide (TBHP), as oxidants, in a biphasic environment. It was found that functioning as a nanoreactor, the prepared catalyst system facilitated the epoxidation of un-functionalized olefins in water, leading to the substantial acceleration of catalytic reaction rates. After the completion of the catalytic activity, the catalyst could be separated easily from the reaction media by manipulating temperature and reused without any activity loss. In effect, the quality of the catalyst remained the same for eight cycles. In a similar vein, the FT-IR spectra and atomic absorption spectroscopy confirmed the great recyclability, durability, and leaching resistance of the catalyst. Graphical Abstract The present study aims to introduce a new catalytic system, namely, thermo-responsive amphiphilic manganese porphyrin-paired ionic co -polymeric hydrogel, poly(N-isopropylacrylamide- co -2-acrylamido-2-methylpropane sulfonic acid sodium)-Mn (III) meso tetra(N-methyl-4-pyridyl) porphine, briefly called P(NIPAM- co-Na AMPS)‐[Mn(TMPyP)].