Immobilization of metalloporphyrin complexes in molecular sieves and their catalytic activity

Interesting Green Catalysis of Cyclohexane Oxidation over Metal Tetrakis(4-carboxyphenyl)porphyrins Promoted by Zinc Sulfide

“…However, few studies have focused on additional exploration to increase catalytic activity of metalloporphyrins via the thiolate ligand for aerobic oxidation of hydrocarbons in heterogeneous systems, or even in homogeneous systems, in practice. , To prevent the undesired reaction in which the thiolate ligand is oxidized to disulfide by molecular oxygen, bulky protecting groups were added around the thiolate axial ligand . First, based on the previously discussed guidelines and studies where an oxygen or a nitrogen atom with a lone electron pair was included in the supporting medium, such as Al 2 O 3, AlOOH, , MCM-41, , ZnO, − silica modified with imidazole groups (CPTMS), and the porous porphyrinic framework materials for axial ligation to the metalloporphyrins, based on enhanced catalytic performance of the Fe- and Mn-porphyrins in which the imidazole and pyridine groups served as the axial ligands. − Second, many new techniques for catalytic cyclohexane oxidation are available that offer high yields of the corresponding main products, − but applications of solvents and nonoxygen­(O 2 ) oxidizing agents, − photochemical techniques, , and the relatively long oxidation time have been disappointing, − which will eventually increase energy consumption and pollution. The biomimetic catalysis system proposed by Lyons is environmentally friendly because it is a green catalysis system that only requires the catalyst, reaction substrate, and oxygen but does not require coreductants, stoichiometric oxidants or photochemical techniques, even any solvents .…”

“…14,15 To prevent the undesired reaction in which the thiolate ligand is oxidized to disulfide by molecular oxygen, bulky protecting groups were added around the thiolate axial ligand. 16 First, based on the previously discussed guidelines and studies where an oxygen or a nitrogen atom with a lone electron pair was included in the supporting medium, such as Al 2 O 3, 17 AlOOH, 18,19 MCM-41, 20,21 ZnO, 22−26 silica modified with imidazole groups (CPTMS), 27 and the porous porphyrinic framework materials 28 for axial ligation to the metalloporphyrins, based on enhanced catalytic performance of the Fe-and Mn-porphyrins in which the imidazole and pyridine groups served as the axial ligands. 29−32 Second, many new techniques for catalytic cyclohexane oxidation are available that offer high yields of the corresponding main products, 33−39 but applications of solvents and nonoxygen(O 2 ) oxidizing agents, 33−39 photochemical techniques, 34,35 and the relatively long oxidation time have been disappointing, 33−38 which will eventually increase energy consumption and pollution.…”

Porphyrins and Phthalocyanines on Solid-State Mesoporous Matrices as Catalysts in Oxidation Reactions

“…In another approach [ 46 ] NaY zeolite and MCM-41 were used for iron(III) porphyrins incorporation using different methods, and screened for the best catalytic system. In the first attempt, the authors loaded HY zeolite and Al-MCM-41 with ferric nitrate.…”

“…Radha Rani tested aforementioned methods for effective encapsulation of iron(III) porphyrins in MCM-41 and NaY zeolite [ 46 ]. The reaction testing the catalytic activity was the oxidation of cyclohexene, using tert -butyl hydroperoxide as an oxidant ( Scheme 6 ).…”

“… Oxidation of cyclohexene using series of porphyrins immobilized on MCM-41. ( A ): 5,10,15,20-tetraphenyl porphyrin; ( B ): 5,10,15,20-tetrapyridyl porphyrin; ( C ) 5,10,15,20-tetraphenyl porphyrin synthesized from pyrrole and benzaldehyde via “ship-in-a-bottle” method; ( D ) 3-aminopropyltrimethoxysilane-modified MCM-41 loaded with 5,10,15,20-tetrakis(pentafluorophenyl) porphyrin iron(III) chloride; ( E ) 5,10,15,20-tetraphenylporphyrin iron(III) chloride; ( F ) 5,10,15,20-tetrakis(pentafluorophenyl)porphyrin iron chloride; ( G ) 3-aminopropyltrimethoxysilane-modified MCM-41 loaded with 5,10,15,20-tetraphenylporphyrin iron(III) chloride [ 46 ]. …”