Synthesis of zinc-porphyrin based multi-arm star Poly(N-isopropylacrylamide) and the effect of topology on photocatalytic performance

Phase Separation and pH-Dependent Behavior of Four-Arm Star-Shaped Porphyrin-PNIPAM4 Conjugates

“…The intensity decrease is due to the restricted mobility of PNIPAM chains in the globular state. Following the assignment of the spectra, , the methine “ b ” resonance of PNIPAM was selected for quantitative analysis of the phase separation process since there is no overlap with other resonances in the 1 H NMR spectrum. The macroscopic manifestation of PP phase separation is also visible to the naked eye (see photographs of NMR cuvettes Figure b) and by optical microscopy (see optical micrographs Figure b).…”

“…Porphyrins covalently linked to polyethylene glycol or PNIPAM in block copolymer formation (i.e., the porphyrin n - block -monomer m ) have also been reported, − although those molecules do not have a porphyrin-centered star-shaped structure. Finally, there have been several studies on Zn­(II) or metal cation-free porphyrin-centered star-shaped conjugates with three-, four-, or eight-arms of PNIPAM, PNIPAM- block -polystyrene, PNIPAM- block -poly­(oligo­(ethylene glycol)­mono methyl ether methacrylate), or PNIPAM- block -poly­( l -lactide) . Thermoresponsive hydrogels based on PNIPAM with tetrakis­(4-aminophenyl)­porphyrin, protoporphyrin IX, or pheophorbide A photosensitizers used as cross-linkers have also been reported.…”

“…Thermoresponsive hydrogels based on PNIPAM with tetrakis­(4-aminophenyl)­porphyrin, protoporphyrin IX, or pheophorbide A photosensitizers used as cross-linkers have also been reported. Many of the abovementioned porphyrin–polymer systems have been investigated as potential drug-release systems, photosensitizers for photodynamic therapy, ,,− antibacterial agents, (photo)­catalysts, ,, magnetic resonance imaging contrast agents, or ultra-sensitive colorimetric thermometers …”

“…67 Thermoresponsive hydrogels based on PNIPAM with tetrakis(4aminophenyl)porphyrin, 68 protoporphyrin IX, 69 or pheophorbide A 69 photosensitizers used as cross-linkers have also been reported. Many of the abovementioned porphyrin−polymer systems have been investigated as potential drug-release systems, 57 photosensitizers for photodynamic therapy, 58,62,66−69 antibacterial agents, 70 (photo)catalysts, 54,64,65 magnetic resonance imaging contrast agents, 71 or ultrasensitive colorimetric thermometers. 63 In this work, we have combined the pH responsivity of freebase (i.e., metal cation-free) tetraphenylporphyrin (TPP) with the phase-separation behavior of the PNIPAM polymer to prepare a "smart" multi-responsive polymeric system.…”

Porphyrin-containing materials for photodegradation of organic pollutants in wastewaters: a review

“…Gao and co-workers 77 reported the synthesis of the Zn( ii ) porphyrin-based multi-arm star polymers Zn 18 , Zn 19 , Zn 20 , and Zn 21 (Fig. 7 and Table 3), where n = 1–4.…”