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Upstream product

• 32195-55-4 5,10,15,20-tetraphenyl-21 H,23-H-porphine manganese(III)chloride 
• 40861-09-4 3-chloroperpropionic acid 
• 94161-44-1 5-chloropervaleric acid 
• 34557-72-7 (5,10,15,20-tetraphenylporphyrinato)manganese(III) chloride 
• 853772-50-6 5,10,15,20-tetraphenylporphyrin-manganese(III) chlorate 
• 132438-45-0 nitritomanganese(III) tetraphenylporphyrin 
• 536-80-1 iodosylbenzene 
• 937-14-4 3-chloro-benzenecarboperoxoic acid 
• 31004-82-7 manganese(II) 5,10,15,20-tetraphenylporphyrinate 
• 74087-85-7 3,3-dimethyldioxirane 
• 58356-65-3 manganese(III) meso-tetraphenylporphyrin acetate 
• 7722-84-1 dihydrogen peroxide 
• 943-39-5 4-nitroperbenzoic acid 
• 19910-09-9 peroxyphenylacetic acid 

Relevant academic research and scientific papers

Kinetics and mechanism of oxidation of manganese(III) acidoporphyrin complexes with hydrogen peroxide

The reactions of manganese(III) acidotetraphenylporphyrin complexes with hydrogen peroxide in an aqueous-organic medium at 288-308 K are studied by spectrophotometry. The reaction is the oxidation of the manganese(III) complex. The spectral and kinetic da

Photochemical generation of manganese(IV)-oxo porphyrins by visible light photolysis of dimanganese(III) μ-oxo bis-porphyrins

Visible light photolysis of dimanganese(III) μ-oxo bis-porphyrins, [MnIII(Por)]2O, was studied in three porphyrin systems with different electronic structures. Direct conversion of manganese (III) μ-oxo dimers to manganese(IV)-oxo porphyrins plus manganese(III) products has been observed in benzene solution upon light irradiation. The spectral signature of MnIV(Por)(O) was further confirmed by production of the same species in the known experiment of the MnIII(Por)Cl with PhI(OAc)2. Continuous irradiation of dimanganese(III) μ-oxo bis-porphyrins in the presence of pyridine or triphenylphosphine gave rise to the formation of MnII(Por)(Py) or MnII(Por)(PPh3) which were stable to be detected. A photo-disproportionation mechanism similar to that for diiron(III) μ-oxo bis-porphyrins was proposed to explain above photochemical behaviors of the three dimanganese(III) μ-oxo bis-porphyrins.

Crystal structure, magnetic and catalytic oxidation properties of manganese(III) tetrakis(ethoxycarbonyl)porphyrin

A new meso-tetraalkyl porphyrin manganese complex, 5,10,15,20-tetrakis(ethoxycarbonyl)porphyrinatomanganese (MnIIITECPCl), had been prepared and characterized by X-ray structure determination. MnIIITECPCl exists as a coordinated dimer in its crystal structure with a weak antiferromagnetic coupling between two Mn(iii) ions. The catalytic oxidation of styrene by MnIIITECPCl was carried out in acetonitrile. MnIIITECPCl was found to be recyclable with a high conversion efficiency when using TBHP as an oxidant and the major product was benzaldehyde. MnIIITECPCl was also reusable by using an PhIO oxidant, but the major products turned out to be phenyl acetaldehyde and styrene epoxide.

Laser flash photolysis generation and kinetic studies of porphyrin-manganese-oxo intermediates. Rate constants for oxidations effected by porphyrin-MnV-oxo species and apparent disproportionation equilibrium constants for porphyrin-MnIV-oxo species

Porphyrin-manganese(V)-oxo and porphyrin-manganese(IV)-oxo species were produced in organic solvents by laser flash photolysis (LFP) of the corresponding porphyrin-manganese(III) perchlorate and chlorate complexes, respectively, permitting direct kinetic studies. The porphyrin systems studied were 5,10,15,20-tetraphenylporphyrin (TPP), 5,10,15,20- tetrakis(pentafluorophenyl)porphyrin (TPFPP), and 5,10,15,20-tetrakis(4- methylpyridinium)porphyrin (TMPyP). The order of reactivity for (porphyrin)MnV(O) derivatives in self-decay reactions in acetonitrile and in oxidations of substrates was (TPFPP) > (TMPyP) > (TPP). Representative rate constants for reaction of (TPFPP)MnV(O) in acetonitrile are k = 6.1 ×105 M-1 s-1 for cis-stilbene and k = 1.4 × 105 M-1 s-1 for diphenylmethane, and the kinetic isotope effect in oxidation of ethylbenzene and ethylbenzene-d10 is kH/kD = 2.3. Competitive oxidation reactions conducted under catalytic conditions display approximately the same relative rate constants as were found in the LFP studies of (porphyrin)MnV(O) derivatives. The apparent rate constants for reactions of (porphyrin)MnIV(O) species show inverted reactivity order with (TPFPP) IV(O) disproportionates to (porphyrin)MnIIIX and (porphyrin)MnV(O), which is the primary oxidant, and the equilibrium constants for disproportionation of (porphyrin)MnIV(O) are in the order (TPFPP) V(O) with (TPFPP)MnIIICl to give (TPFPP)MnIV-(O) (k = 5 × 108 M-1 s -1) and disproportionation reaction of (TPP)MnIV(O) to give (TPP)MnV(O) and (TPP)-MnIIIX (k ≈ 2.5 × 109 M-1 s-1) were observed. The relative populations of (porphyrin)MnV(O) and (porphyrin)MnIV(O) were determined from the ratios of observed rate constants for self-decay reactions in acetonitrile and oxidation reactions of cis-stilbene by the two oxo derivatives, and apparent disproportionation equilibrium constants for the three systems in acetonitrile were estimated. A model for oxidations under catalytic conditions is presented.

Laser Flash Photolysis Studies of Nitritomanganese(III) Tetraphenylporphyrin. Reactions of O2, NO, and Pyridine with Manganese(II) Tetraphenylporphyrin

Laser photolysis of nitritomanganese(III) tetraphenylporphyrin. MnIIITPP(ONO) (1), in degassed toluene gives manganese(II) tetraphenylporphyrin, MnIITPP (2), plus NO2. The quantum yield, Φ, for the formation of MnII-TPP is dependent on the excitation wavelength: Φ = 0.045 at 355 nm and Φ = 0.0064 at 532 nm. Continuous photolysis studies reveal that the quantum yield for the net photodecomposition of 1 is much smaller (10-4). Thus, MnIITPP produced by laser photolysis of MnIIITPP(ONO) mostly returns to 1 by recombination with NO2 according to second-order kinetics with a rate constant 2.2 × 109 M-1 s-1. The kinetics for the reactions of MnIITPP with O2, NO, and pyridine were investigated in detail. In aerated toluene, MnIITPP reversibly reacts with oxygen to yield the dioxygen adduct, MnTPP(O2) (3). The rate constants, kf(O2) and kb(O2), for the formation and dissociation of 3 at 300 K were determined to be 1.93 × 107 M-1 s-1 and 9.0 × 104 s-1, respectively, and the equilibrium constant, kf(O2)/kb(O2), is therefore 2.1 × 102 M-1. MnIITPP reacts with pyridine to give MnII-TPP(Py) with a rate constant of 9.5 × 108 M-1 s-1. MnIITPP reacts with NO to yield nitrosylmanganese porphyrin, MnIITPP(NO), with the rate constant 5.3 × 108 M-1 s-1. The association reactions of MnIITPP with NO, pyridine, O2, and NO2 are discussed in comparison with those of other metalloporphyrins.

Photochemical reduction of nitrate and nitrite by manganese and iron porphyrins

New nitrate and nitrite complexes of metalloporphyrins have been synthesized and crystallographically characterized, and their photochemistry has been examined. Irradiation of Mn(TPP)(NO3) and Mn(TPP)(NO2) (where TPP = 5,10,15,20-tetraphenylporphyrinate(2-)) produces the high-valent metal-oxo species O=MnIV(TPP) quantitatively, with quantum yields of 1.58 × 10-4 and 5.30 × 10-4, respectively. This metal-oxo species is capable of oxidizing substrates, as demonstrated in reactions with styrene or triphenylphosphine. Mn(TPP)(NO2) is formed as an intermediate in the complete photolysis of Mn(TPP)(NO3). Similarly, the photochemistry of Fe(TPP)(NO3) produces substrate oxidation, including C-H hydroxylation, which suggests the photochemical formation of O=FeIV(TPP.+) as the active oxidant. Remarkably, all three oxygen atoms of the initially bound NO3- can be used for substrate oxidation. The X-ray crystal structures of Mn(TPP)(NO3)·2C6H6 and Mn(TPP)(NO2)·C6H6 have been solved. In the nitrate complex Mn(TPP)(NO3), the average Mn-pyrrole N distance is 2.007 A?, with the metal 0.21 A? above the mean plane of the nitrogen atoms. The nitrate ion is coordinated in a unidentate fashion with a Mn-O bond length of 2.101 A?. Mn(TPP)(NO2) is the first metalloporphyrin complex with oxygen-bound nitrite. The average Mn-pyrrole nitrogen distance is 2.012 A?, with the metal 0.23 A? above the mean plane of the nitrogen atoms. The nitrite ion is coordinated through one of the oxygens, with a Mn-O bond length of 2.059 A?. Crystal data for Mn(TPP)(NO3)·2C6H6 at -76°C: space group P1, a = 13.271 (4) A?, b = 13.610 (5) A?, c = 12.880 (3) A?, α = 111.44 (2)°, β = 95.71 (2)°, γ = 85.50 (3)°, V = 2152 (2) A?3, Z = 2, RF = 0.063, RwF = 0.086 for 408 variables and 4890 unique data with I > 2.58σ(I). Crystal data for Mn(TPP)(NO2)·C6H6: space group Pccn, a = 21.631 (11) A?, b = 19.941 (12) A?, c = 17.991 (6) A?, V = 7760 (7) A?3, Z = 8, RF = 0.062, RwF = 0.096 for 543 variables and 3820 unique data with I > 2.58σ(I).

Metalloporphyrin photochemistry with matrix isolation

The photochemistry of a number of metalloporphyrin oxoanion complexes has been examined by matrix isolation techniques, using both frozen solvent glasses and polymer films. After an extensive search for a noncoordinating, unreactive, glassing solvent, a 3:1 mixture of 2,2-dimethylbutane and tert-butylbenzene was found to work well at temperatures below 70 K. Alternatively, the photochemistry of metalloporphyrins was monitored in polymer films by the evaporation on a sapphire window of metalloporphyrin solutions in toluene containing either poly(methyl methacrylate) or poly(α-methylstyrene). The polymer films have the added advantage of a greatly increased temperature range, providing diffusional isolation even at room temperature. The photoreduction of the metal by homolytic α-bond cleavage and loss of the axial ligand appears to be a general mechanism for all metalloporphyrin complexes examined. The formation of metal-oxo species from photolysis of metalloporphyrin oxoanion complexes in solution derives from secondary, thermal reactions.

Spontaneous Formation of Reactive Oxometal Porphyrins by Oxygen Atom Transfer from Dioxirane

Oxygen atom transfer to manganese(II) tetraphenylporphyrin (tpp) and iron(II) tetramesitylporphyrin (tmp) is readily effected at IV(tpp) and O=Fe

OXOMANGANESE(IV) PORPHYRINS IDENTIFIED BY RESONANCE RAMAN AND INFRARED SPECTROSCOPY: WEAK BONDS AND THE STABILITY OF THE HALF-FILLED T2g SUBSHELL.

The Mn**I**V-O stretching frequency is identified at 754 cm** minus **1 in resonance Raman (RR) and infrared (IR) spectra of Mn**I**V porphyrins prepared by electrooxidation of ClMn**I**I**ITMP, ClMn**I**I**ITPP and ClMn**I**I**IOEP in CH//3CN containing