66746-94-9

Upstream product

• 16591-56-3 5,10,15,20-tetraphenyl porphyrin iron 
• 593-75-9 methyl isocyanate 
• 16456-81-8 meso-tetraphenylporphyrin iron(III) chloride 
• 201230-82-2 carbon monoxide 
• 124-38-9 carbon dioxide 
• 57715-43-2 [iron(III)(5,10,15,20-tetraphenyl-21H,23H-porphine)] perchlorate 

Relevant academic research and scientific papers

Bio-Inspired Carbon Monoxide Sensors with Voltage-Activated Sensitivity

Carbon monoxide (CO) outcompetes oxygen when binding to the iron center of hemeproteins, leading to a reduction in blood oxygen level and acute poisoning. Harvesting the strong specific interaction between CO and the iron porphyrin provides a highly selective and customizable sensor. We report the development of chemiresistive sensors with voltage-activated sensitivity for the detection of CO comprising iron porphyrin and functionalized single-walled carbon nanotubes (F-SWCNTs). Modulation of the gate voltage offers a predicted extra dimension for sensing. Specifically, the sensors show a significant increase in sensitivity toward CO when negative gate voltage is applied. The dosimetric sensors are selective to ppm levels of CO and functional in air. UV/Vis spectroscopy, differential pulse voltammetry, and density functional theory reveal that the in situ reduction of FeIII to FeII enhances the interaction between the F-SWCNTs and CO. Our results illustrate a new mode of sensors wherein redox active recognition units are voltage-activated to give enhanced and highly specific responses.

Comparative FTIR study of the cobalt and iron porphyrin reactions with CO. Does cobalt porphyrin form a bis-carbonyl complex in the Ar matrix?

The adducts of Co(II)(TPP) and Fe(II)TPP (TPP is meso-tetraphenyl-porphyrinato dianion) with carbon monoxide in Ar matrix at 10 K have been studied by FTIR spectroscopy using CO, C18O and their equimolar mixture. It is shown that both metals ma

Synthetic Iron Porphyrins for Probing the Differences in the Electronic Structures of Heme a3, Heme d, and Heme d1

A variety of heme derivatives are pervasive in nature, having different architectures that are complementary to their function. Herein, we report the synthesis of a series of iron porphyrinoids, which bear electron-withdrawing groups and/or are saturated at the β-pyrrolic position, mimicking the structural variation of naturally occurring hemes. The effects of the aforementioned factors were systematically studied using a combination of electrochemistry, spectroscopy, and theoretical calculations with the carbon monoxide (CO) and nitric oxide (NO) adducts of these iron porphyinoids. The reduction potentials of iron porphyrinoids vary over several hundreds of millivolts, and the X-O (X = C, N) vibrations of the adducts vary over 10-15 cm-1. Density functional theory calculations indicate that the presence of electron-withdrawing groups and saturation of the pyrrole ring lowers the π?-acceptor orbital energies of the macrocycle, which, in turn, attenuates the bonding of iron to CO and NO. A hypothesis has been presented as to why cytochrome c containing nitrite reductases and cytochrome cd1 containing nitrite reductases follow different mechanistic pathways of nitrite reduction. This study also helps to rationalize the choice of heme a3 and not the most abundant heme b cofactor in cytochrome c oxidase.

Carbon monoxide coordination by iron(II) meso-mono-4-pyridyltriphenylporphyrinate (FeM4PyTPP) and its structure in sublimed layers

Interaction of CO with sublimed layers of iron(II) meso-mono-4-pyridyltriphenylporphyrinate (FeM4PyTPP) resulting in the formation of known mono- and dicarbonyl complexes was studied using IR spectroscopy. The frequency of the stretching vibration of the coordinated CO in the monocarbonyl complex was found to be ～20 cm-1 higher than in the complex with iron meso-tetraphenylporphyrinate (FeTPP), with the former complex being significantly more stable than the latter. The differences observed in CO coordination by porphyrins with close structures are explained by the formation, in the FeM4PyTPP sublimed layers, of oligomeric structures where the pyridyl group of one molecule is coordinated by the metal ion of the neighboring molecule. This conclusion is confirmed by a comparative analysis of IR spectra of FeM4PyTPP and FeTPP in the regions of structurally sensitive vibrations.

Iron porphyrin-catalyzed reduction of CO2. Photochemical and radiation chemical studies

Several iron porphyrins have been reduced by photochemical and radiation chemical methods, in organic solvents and in aqueous solutions, from FeIIIP to FeIIP to FeIP and beyond. In aqueous solutions, the FeIP state is relatively stable for the tetrakis(N-methyl-2-pyridyl)porphyrin at high pH but is shorter lived in neutral and acidic solutions. The FeIP state of tetrakis(N-methyl-3-pyridyl)porphyrin and tetrakis(N-methyl-4-pyridyl)-porphyrin are short-lived at any pH. Decay of FeIP is accelerated by H+ and by CO2, probably via reaction with the Fe0P state formed upon disproportionation of FeIP. These reactions may lead to formation of H2 and CO, respectively, and to formation of the chlorin, FeIIPH2, as a side product. The FeIP state is also observed as a stable product in several organic solvents. This is observed by photolysis of iron tetraphenylporphyrin and several of its derivatives (e.g., trimethyl-, dichloro- and pentafluorophenyl), mainly in dimethylformamide and acetonitrile solutions, using triethylamine as a reductive quencher. Further photoreduction in the presence of CO2 results in catalyzed reduction of CO2 to CO and formation of (CO)-FeIIP. The yield of free CO increases with time of photolysis and reaches turnover numbers of approximately 70 molecules of CO per porphyrin molecule.

Biomimetic oxidation with molecular oxygen. Selective carbon-carbon bond cleavage of 1,2-diols by molecular oxygen and dihydropyridine in the presence of iron-porphyrin catalysts

The selective carbon-carbon bond cleavage of 1,2-diols in the presence of an iron-porphyrin complex, molecular oxygen, and 1-benzyl-3-carbamoyl-1,4-dihydropyridine is reported. The C-C bonds of aryl-substituted ethane-1,2-diols were cleaved exclusively to aldehydes or ketones as the oxidation products at room temperature. The reaction rates were influenced by the steric hindrance of the substituents both in the catalysts and diols, but no differences in the reactivities were observed between the two stereo isomers (meso and dl) of diols. A kinetic analysis of this bond cleavage reaction is consistent with the reaction mechanism consisting of the initial binding of diol on the active catalyst forming an intermediate complex and its subsequent breakdown in the rate-determining step of the catalytic cycle. The initial binding step is favorable for electron-deficient diols and is influenced by steric hindrance, whereas the rate-determining bond cleavage step is accelerated by electron-rich diols and unaffected by the steric effect. The mechanism of this diol cleavage reaction is discussed on the basis of these observations. The selective carbon-carbon bond cleavage of 1,2-diols in the presence of an iron-porphyrin complex, molecular oxygen, and 1-benzyl-3-carbamoyl-1,4-dihydropyridine is reported. The C-C bonds of aryl-substituted ethane-1,2-diols were cleaved exclusively to aldehydes or ketones as the oxidation products at room temperature. The reaction rates were influenced by the steric hindrance of the substituents both in the catalysts and diols, but no differences in the reactivities were observed between the two stereo isomers (meso and dl) of diols. A kinetic analysis of this bond cleavage reaction is consistent with the reaction mechanism consisting of the initial binding of diol on the active catalyst forming an intermediate complex and its subsequent breakdown in the rate-determining step of the catalytic cycle.