16887-00-6Relevant articles and documents
Kligler, D.,Rozenberg, Z.,Rokni, M.
, p. 319 - 321 (1981)
Halperin, J.,Taube, H.
, p. 3319 - 3320 (1950)
Blaunstein, R. P.,Christophorou, L. G.
, p. 1526 - 1531 (1968)
A Bioinspired Molybdenum Catalyst for Aqueous Perchlorate Reduction
Bi, Eric Y.,Gao, Jinyu,Liu, Jinyong,Palmer, Jacob,Ren, Changxu,Sun, Jiaonan,Wu, Yiying,Yang, Peng,Zhu, Mengqiang
, p. 7891 - 7896 (2021)
Perchlorate (ClO4-) is a pervasive, harmful, and inert anion on both Earth and Mars. Current technologies for ClO4- reduction entail either harsh conditions or multicomponent enzymatic processes. Herein, we report a heterogeneous (L)Mo-Pd/C catalyst directly prepared from Na2MoO4, a bidentate nitrogen ligand (L), and Pd/C to reduce aqueous ClO4- into Cl- with 1 atm of H2 at room temperature. A suite of instrument characterizations and probing reactions suggest that the MoVI precursor and L at the optimal 1:1 ratio are transformed in situ into oligomeric MoIV active sites at the carbon-water interface. For each Mo site, the initial turnover frequency (TOF0) for oxygen atom transfer from ClOx- substrates reached 165 h-1. The turnover number (TON) reached 3840 after a single batch reduction of 100 mM ClO4-. This study provides a water-compatible, efficient, and robust catalyst to degrade and utilize ClO4- for water purification and space exploration.
Jackson, D. T.,Parsons, J. L.
, p. 14 - 15 (1937)
Christou, G.,Heinrich, D.,Money, J. K.,Rambo, J. R.,Huffman, J. C.,Folting, K.
, p. 1723 - 1728 (1989)
Fairbrother
, p. 2419 - 2419 (1922)
Chia, Y.-T.,Connick, R. E.
, p. 1518 - 1519 (1959)
Haight, G. P.
, p. 4718 - 4721 (1954)
Copper(II) catalyses the reduction of perchlorate by both formaldehyde and by dihydrogen in aqueous solutions
Shamir, Dror,Meyerstein, Dan,Zilbermann, Israel,Burg, Ariela,Albo, Yael,Shames, Alexander I.,Vainer, Radion,Borojovich, Eitan J.C.,Yardeni, Guy,Kornweitz, Haya,Maimon, Eric
, p. 2905 - 2912 (2018)
During an effort to synthesize the trans-III-copper(II) complex with 1,4,8,11-tetramethyl-pyro-phosphonate-1,4,8,11-tetra-aza-cyclo-tetradecane, using only perchlorate salts, it was noted that the perchlorate is reduced to chloride. Analysis of the reactions leading to this surprising result points out that Cu(H2O)42+ catalyzes the reduction of perchlorate by H2 and by CH2O. These reactions are slow at room temperature and ambient pressures. A plausible mechanism, supported by DFT calculations, is proposed pointing out that the role of CuH+ under mild conditions cannot be ignored.
Thorpe,Eccles
, p. 856 - 856 (1876)
Production of Sb(IV) chloro complex by flash photolysis of the corresponding Sb(III) and Sb(V) complexes in CH3CN and CHCl3
Shinohara, Nobuyoshi,Ohshima, Masaaki
, p. 1599 - 1604 (2000)
[SbCl6]2- was formed in the flash photolysis of [SbCl6]3- or [SbCl6]- in both solutions of CH3CN and CHCl3 in the presence of an excess of chloride. [SbCl6]2- had absorption maxima at 293, 328, and 390 nm in CH3CN. A similar absorption spectrum of [SbCl6]2- was also obtained in CHCl3. The lifetime of [SbCl6]2- was much shorter in CHCl3 than in CH3CN. [SbCl6]- was easily reduced to [SbCl6]3- upon continuous UV- irradiation in CH3CN as well as in CHCl3. On the other hand, [SbCl6]3- was oxidized to [SbCl6]- in CHCl3 in the presence of oxygen, but was not in CH3CN. The spectrum and the decay rate of [SbCl6]2- were not essentially affected by oxygen in both solutions of CH3CN and CHCl3.
Furman, S. C.,Garner, C. S.
, p. 2333 - 2337 (1952)
Kinetics and Mechanism of the Chlorine Dioxide-Tetrathionate Reaction
Horvath, Attila K.,Nagypal, Istvan,Epstein, Irving R.
, p. 10063 - 10068 (2003)
The chlorine-dioxide-tetrathionate reaction was studied spectrophotometrically in the pH range 4.55-5.55 at 25.0 ± 0.2 °C and 0.5 M ionic strength adjusted with sodium acetate as a buffer component. The stoichiometry was found to be S4O6 2- + 4°ClO2 + 5H2O → 4SO42- + ClO3- + 3Cl- + 10H+with small deviations at high excess of chlorine dioxide with no chloride ion initially present. The initial presence of chloride not only affects the stoichiometry but also accelerates the reaction. A 14-step mechanism, including four known and two newly proposed intermediates, is suggested to describe the observed behavior of the system.
Farkas, L.,Lewin, M.,Bloch, R.
, p. 1988 - 1991 (1949)
Kern, D. M.,Chang-Hwan Kim
, p. 5309 - 5313 (1965)
First Micelle-Free Photoredox Catalytic Access to Hydrated Electrons for Syntheses and Remediations with a Visible LED or even Sunlight
Naumann, Robert,Goez, Martin
, p. 17557 - 17567 (2018)
Hydrated electrons are super-reductants, yet can be generated with visible light when two photons are pooled, most efficiently through storing the energy of the first photon in a radical pair formed by the reduction of an excited catalyst by a sacrificial donor. All previous such systems for producing synthetically useable amounts of hydrated electrons with an LED in the visible range had to resort to compartmentalization by SDS micelles to curb the performance-limiting recombination of the pair. To overcome micelle-imposed constraints on sustainability and applications, we have instead attached carboxylate groups to a ruthenium (tris)bipyridyl catalyst such that its pentaanionic radical strongly repels the dianionic radical of the bioavailable donor urate. We have explored the influence of the Coulombic interactions on the electron generation by a time-resolved study from microseconds to hours, including for comparison the unsubstituted complex, which forms a monocationic radical, with and without SDS micelles. The new homogeneous electron source is best with regard to stability and total electron output; it has a broader synthetic scope because it does not entail micellar shielding of less hydrophilic compounds, which particularly facilitates cross-couplings; and it tolerates supramolecular containers as carriers of water-insoluble substrates or products. As an application in the field, we demonstrate the solar remediation of a recalcitrant chloro-organic bulk chemical.
Matrix Effect on Hydrogen Atom Tunneling from Alkane to Free Deuterium Atoms in Cryogenic Solid
Ichikawa, Tsuneki,Kagei, Koh-Ichi,Tachikawa, Hiroto,Ishitani, Yoshinobu
, p. 6288 - 6294 (1999)
ESR study on alkyl radicals generated in deuterated organic matrixes at 77 K by hydrogen atom tunneling from alkane molecules to free deuterium atoms has been carried out for elucidating control factors for the tunneling. For small alkane molecules, the tunneling rate is determined by the height of the potential energy barrier for the tunneling. For larger molecules in glassy matrixes, the rate decreases with increasing number and length of alkyl chains bonded to a carbon atom to be hydrogen abstracted. The tunneling rate from antepenultimate tertiary carbon is much slower than that from penultimate secondary carbon, even the potential energy barrier is lower. This abnormal effect is explained as being due to the steric hindrance by matrix molecules to the deformation of alkane molecules during the reaction. The alkyl chains surrounded by matrix molecules prevent the deformation of the chemical bonds of the carbon atom from the initial sp3 to the final sp2 configuration, which may cause the increase of the thickness of the potential energy barrier and thereby decrease of the tunneling rate. Free deuterium atoms in a crystalline adamantane matrix selectively abstract hydrogen atoms from the antepenultimate tertiary carbon, probably due to less steric hindrance to the deformation.
Hendrixson
, p. 389 - 389 (1912)
King, W. R.,Garner, C. S.
, p. 29 - 33 (1954)
Gleason, E. H.,Mino, G.,Thomas, W. M.
, p. 447 - 450 (1957)
Burns, E. A.,Muraca, R. F.
, p. 1316 - 1319 (1960)
Russell, C. D.
, p. 1291 - 1293 (1963)
Fox,Curran
, p. 1595 (1961)
Reactions of negative ions with ClN3 at 300 K
Eyet, Nicole,Freel, Keith,Heaven, Michael C.,Viggiano
, p. 6832 - 6836 (2010)
The reactivity of ClN3 with 17 negative ions has been investigated at 300 K. The electron affinity (EA) of ClN3 was bracketed to be between that of NO2 and N3, giving EA(ClN3) = 2.48 ± 0.20 eV, in agr
Photocatalytic Degradation of Rhodamine B using Aqueous Free-Base Porphyrin and Metalloporphyrins of Mn, Fe and Sn
Gokakakar, S. D.,Salker, A. V.
, p. 834 - 840 (2022/03/16)
The aqueous-porphyrins used in clinical studies for photodynamic therapy (PDT) are exploited as the photocatalysts for the first time in the photodegradation of rhodamine B in the acetone medium. The porphyrins such as free-base porphyrin TPPS4 and MnTPPS4Cl, FeTPPS4Cl, a dimer (FeTPPS4)2-O and SnTPPS4Cl2 were synthesized and characterized by ultraviolet-visible, infrared, 1H NMR, fluorescence spectroscopies and elemental analysis. The band-gap energies of the respective porphyrins were determined using DRS spectroscopy. They have shown 100% degradation of the dye within 25-40 min, which was confirmed by HPLC and ion-chromatography. This has revealed that semiconductor aqueous-porphyrins may be a good choice as photocatalysts in the photodegradation of rhodamine B dye.
Selective C-H halogenation over hydroxylation by non-heme iron(iv)-oxo
Rana, Sujoy,Biswas, Jyoti Prasad,Sen, Asmita,Clémancey, Martin,Blondin, Geneviève,Latour, Jean-Marc,Rajaraman, Gopalan,Maiti, Debabrata
, p. 7843 - 7858 (2018/10/31)
Non-heme iron based halogenase enzymes promote selective halogenation of the sp3-C-H bond through iron(iv)-oxo-halide active species. During halogenation, competitive hydroxylation can be prevented completely in enzymatic systems. However, synthetic iron(iv)-oxo-halide intermediates often result in a mixture of halogenation and hydroxylation products. In this report, we have developed a new synthetic strategy by employing non-heme iron based complexes for selective sp3-C-H halogenation by overriding hydroxylation. A room temperature stable, iron(iv)-oxo complex, [Fe(2PyN2Q)(O)]2+ was directed for hydrogen atom abstraction (HAA) from aliphatic substrates and the iron(ii)-halide [FeII(2PyN2Q)(X)]+ (X, halogen) was exploited in conjunction to deliver the halogen atom to the ensuing carbon centered radical. Despite iron(iv)-oxo being an effective promoter of hydroxylation of aliphatic substrates, the perfect interplay of HAA and halogen atom transfer in this work leads to the halogenation product selectively by diverting the hydroxylation pathway. Experimental studies outline the mechanistic details of the iron(iv)-oxo mediated halogenation reactions. A kinetic isotope study between PhCH3 and C6D5CD3 showed a value of 13.5 that supports the initial HAA step as the RDS during halogenation. Successful implementation of this new strategy led to the establishment of a functional mimic of non-heme halogenase enzymes with an excellent selectivity for halogenation over hydroxylation. Detailed theoretical studies based on density functional methods reveal how the small difference in the ligand design leads to a large difference in the electronic structure of the [Fe(2PyN2Q)(O)]2+ species. Both experimental and computational studies suggest that the halide rebound process of the cage escaped radical with iron(iii)-halide is energetically favorable compared to iron(iii)-hydroxide and it brings in selective formation of halogenation products over hydroxylation.