1
|
The oxidation of the uranium(IV)tetrachloride by the octacyanotungstate(V) and the octacyanomolybdate(V) ions in perchloric acid medium: A kinetic study. REACTION KINETICS MECHANISMS AND CATALYSIS 2022. [DOI: 10.1007/s11144-022-02297-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
|
2
|
Dennis CR, van Zyl GJ, Fourie E, Basson SS, Swarts JC. A kinetic study of the oxidation of the tetrakisoxalatouranate(IV) ion by the octacyanotungstate(V) and the octacyanomolybdate(V) ions in an acidic oxalate buffer medium. REACTION KINETICS MECHANISMS AND CATALYSIS 2021. [DOI: 10.1007/s11144-021-02109-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
|
3
|
Dennis CR, van Zyl GJ, Fourie E, Basson SS, Swarts JC. A kinetic study of the oxidation of the tetrakisoxalatouranate(IV) ion by the hexacyanoferrate(III) ion in an oxalate buffer medium. REACTION KINETICS MECHANISMS AND CATALYSIS 2021. [DOI: 10.1007/s11144-021-01938-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
|
4
|
Robert Dennis C, Potgieter IM, Basson SS. A kinetic study of the oxidation of formaldehyde by the octacyanomolybdate(V) ion in aqueous alkaline medium. REACTION KINETICS MECHANISMS AND CATALYSIS 2011. [DOI: 10.1007/s11144-011-0342-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
|
5
|
Galán M, Jiménez R, Sánchez F. Kinetic Salt Effects on the Outer-sphere Electron-transfer Reaction between Hexacyanoferrate(II) and Pentaammineaquocobalt(III). ACTA ACUST UNITED AC 2010. [DOI: 10.1002/bbpc.19930970104] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
|
6
|
Robert Dennis C, Potgieter IM, Basson SS. A kinetic study of the reduction of the octacyanomolybdate(V) ion by the hydroxide ion. REACTION KINETICS MECHANISMS AND CATALYSIS 2009. [DOI: 10.1007/s11144-009-0115-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
|
7
|
Synthesis and characterization of one- and two-dimensional octacyanometalate(V) networks: {[trans-MII(DMF)4][cis-MII(DMF)4]2[MV(CN)8]2}n (MII=Mn, Fe, Ni; MV=Mo, W). Polyhedron 2007. [DOI: 10.1016/j.poly.2007.01.049] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
|
8
|
Gomez-Tagle P, Vargas-Zúñiga I, Taran O, Yatsimirsky AK. Solvent Effects and Alkali Metal Ion Catalysis in Phosphodiester Hydrolysis. J Org Chem 2006; 71:9713-22. [PMID: 17168589 DOI: 10.1021/jo061780i] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
The kinetics of the alkaline hydrolysis of bis(p-nitrophenyl) phosphate (BNPP) have been studied in aqueous DMSO, dioxane, and MeCN. In all solvent mixtures the reaction rate steadily decreases to half of its value in pure water in the range of 0-70 vol % of organic cosolvent and sharply increases in mixtures with lower water content. Correlations based on different scales of solvent empirical parameters failed to describe the solvent effect in this system, but it can be satisfactorily treated in terms of a simplified stepwise solvent-exchange model. Alkali metal ions catalyze the BNPP hydrolysis but do not affect the rate of hydrolysis of neutral phosphotriester p-nitrophenyl diphenyl phosphate in DMSO-rich mixtures. The catalytic activity decreases in the order Li+ > Na+ > K+ > Rb+ > Cs+. For all cations except Na+, the reaction rate is first-order in metal ion. With Na+, both first- and second-order kinetics in metal ions are observed. Binding constants of cations to the dianionic transition state of BNPP alkaline hydrolysis are of the same order of magnitude and show a similar trend as their binding constants to p-nitrophenyl phosphate dianion employed as a transition-state model. The appearance of alkali metal ion catalysis in a medium, which solvates metal ions stronger than water, is attributed to the increased affinity of cations to dianions, which undergo a strong destabilization in the presence of an aprotic dipolar cosolvent.
Collapse
Affiliation(s)
- Paola Gomez-Tagle
- Facultad de Química, Universidad Nacional Autónoma de México, 04510 México D.F., México
| | | | | | | |
Collapse
|
9
|
Withers JR, Ruschman C, Parkin S, Holmes SM. One- and three-dimensional octacyanometalate(IV) networks constructed via a building block approach: {[trans-NiII(tn)2(OH2)][trans-NiII(μ-NC)2(tn)2][(μ-NC)3MIV(CN)5]·6H2O} (MIV=Mo, W) and Cs4[CuII(OH2)4]2[CuII(NH3)]4[MoIV(CN)8]4·2H2O. Polyhedron 2005. [DOI: 10.1016/j.poly.2005.06.052] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
|
10
|
Abstract
The oxidation of cysteine by [Mo(CN)(8)](3-) in deoxygenated aqueous solution at a moderate pH is strongly catalyzed by Cu(2+), to the degree that impurity levels of Cu(2+) are sufficient to dominate the reaction. Dipicolinic acid (dipic) is a very effective inhibitor of this catalysis, such that with 1 mM dipic, the direct oxidation can be studied. UV-vis spectra and electrochemistry show that [Mo(CN)(8)](4-) is the Mo-containing product. Cystine and cysteinesulfinate are the predominant cysteine oxidation products. The stoichiometric ratio (Deltan(Mo(V))/Deltan(cysteine)) of 1.4 at pH 10.8 is consistent with this product distribution. At pH 1.5, the reaction is quite slow and yields intractable kinetics. At pH 4.5, the rates are much faster and deviate only slightly from pseudo-first-order behavior. With 2 mM PBN (N-phenyl-tert-butyl nitrone) present at pH 4.5, the reaction rate is about 20% less and shows excellent pseudo-first-order behavior, but the stoichiometric ratio is not significantly changed. The rates also display a significant specific cation effect. In the presence of spin-trap PBN, the kinetics were studied over the pH range 3.48-12.28, with [Na(+)] maintained at 0.09-0.10 M. The rate law is -d[Mo(V)]/dt = k[cysteine](tot)[Mo(V)], with k = {2(k(b)K(a1)K(a2)[H(+)] + k(c)K(a1)K(a2)K(a3))}/([H(+)](3) + K(a1)[H(+)](2) + K(a1)K(a2)[H(+)] + K(a1)K(a2)K(a3)), where K(a1), K(a2), and K(a3) are the successive acid dissociation constants of HSCH(2)CH(NH(3)(+))CO(2)H. Least-squares fitting yields k(b) = (7.1 +/- 0.4) x 10(4) M(-1) s(-1) and k(c) = (2.3 +/-0.2) x 10(4) M(-1) s(-1) at mu = 0.1 M (NaCF(3)SO(3)) and 25 degrees C. A mechanism is inferred in which k(b) and k(c) correspond to electron transfer to Mo(V) from the thiolate forms of anionic and dianionic cysteine.
Collapse
Affiliation(s)
- Meiling Hung
- Department of Chemistry, Auburn University, Alabama 36849, USA
| | | |
Collapse
|
11
|
Withers JR, Ruschmann C, Bojang P, Parkin S, Holmes SM. Synthesis and Structural Characterization of Bi- and Trimetallic Octacyanometalate(IV) Complexes: [Δ,Λ-MII(en)3][cis-MII(en)2(OH2)][MIV(CN)8]·2H2O and [cis-MII(en)2(OH2)]2[(μ-NC)2MIV(CN)6]·4H2O (MII = Mn, Co, Ni; MIV = Mo, W). Inorg Chem 2004; 44:352-8. [PMID: 15651881 DOI: 10.1021/ic048936m] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Treatment of [M(II)(en)(3)][OTs](2) or methanolic ethylenediamine solutions containing transition metal p-toluenesulfonates (M(II) = Mn, Co) with aqueous K(4)M(IV)(CN)(8).2H(2)O or Cs(3)M(V)(CN)(8) (M(IV) = Mo, W; M(V) = Mo) affords crystalline clusters of [M(II)(en)(3)][cis-M(II)(en)(2)(OH(2))(mu-NC)M(IV)(CN)(7)].2H(2)O (M(IV) = Mo; M(II) = Mn, 1; Ni, 5; M(IV) = W; M(II) = Mn, 2; Ni, 6) and [cis-M(II)(en)(2)(OH(2))](2)[(mu-NC)(2)M(IV)(CN)(6)].4H(2)O (M(IV) = Mo; M(II) = Co, 3; Ni, 7; M(IV) = W; M(II) = Co, 4) stoichiometry. Each cluster contains cis-M(II)(en)(2)(OH(2))(mu-NC)(2+) units that likely result from dissociative loss of en from [M(II)(en)(3)](2+), affording cis-M(II)(en)(2)(OH(2))(2)(2+) intermediates that are trapped by M(IV)(CN)(8)(4-).
Collapse
Affiliation(s)
- Jeffrey R Withers
- Department of Chemistry, University of Kentucky, Lexington, Kentucky 40506-0055, USA
| | | | | | | | | |
Collapse
|
12
|
Saha B, Hung M, Stanbury DM. Reduction of octacyanomolybdate(V) by thioglycolic acid in aqueous media. Inorg Chem 2002; 41:5538-43. [PMID: 12377051 DOI: 10.1021/ic025702z] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
In aqueous media at 25 degrees C [Mo(CN)(8)](3-) is reduced by thioglycolic acid (HSCH(2)COOH, TGA), and the reaction is strongly accelerated by the presence of trace amounts of copper ions. Dipicolinic acid (dipic) is an effective inhibitor of the copper catalysis. Both with and without dipic the reaction has the stoichiometry 2[Mo(CN)(8)](3-) + 2TGA --> 2[Mo(CN)(8)](4-) + RSSR, where RSSR is the disulfide derived from formal oxidative dimerization of TGA. In the presence of dipic, PBN (N-tert-butyl-alpha-phenyl-nitrone), and with a large excess of TGA the rate law for consumption of [Mo(CN)(8)](3-) is first order in both [TGA] and [Mo(CN)(8)(3-)]. The complex pH dependence is consistent with (-)SCH(2)CO(2)(-) being highly reactive (k = 1.8 x 10(4) M(-1) s(-1)), the monoanion being less reactive, and HSCH(2)CO(2)H being unreactive. A mechanism is proposed in which the dianion undergoes electron transfer to [Mo(CN)(8)](3-), thus generating the thiyl radical. Analysis of the electron-transfer rate constant in terms of Marcus theory yields an effective self-exchange rate constant for the thiolate/thiyl redox couple that is in reasonable agreement with the value derived previously from the reaction of TGA with [IrCl(6)](2-). When copper catalysis is inhibited, the two reactions differ substantially in that the yield of (-)O(3)SCH(2)CO(2)(-) is significant for [IrCl(6)](2-) but undetectable for [Mo(CN)(8)](3-).
Collapse
Affiliation(s)
- Basudeb Saha
- Department of Chemistry, Auburn University, Auburn, AL 36849, USA
| | | | | |
Collapse
|
13
|
Dennis C, Basson SS. The oxidation of octacyanomolybdate(IV) and octacyanotungstate(IV) by nitrous acid. Polyhedron 1997. [DOI: 10.1016/s0277-5387(97)00134-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
|
14
|
|
15
|
Electron-transfer kinetics and mechanism of the reduction of octacyanometallates(IV) (M = Mo, W) by hydroxide ion in aqueous solution. TRANSIT METAL CHEM 1993. [DOI: 10.1007/bf00191133] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
|
16
|
Octacyano and Oxo- and Nitridotetracyano Complexes of Second and Third Series Early Transition Metals. ADVANCES IN INORGANIC CHEMISTRY 1993. [DOI: 10.1016/s0898-8838(08)60185-3] [Citation(s) in RCA: 51] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
|
17
|
Huie RE, Shoute LCT, Neta P. Temperature dependence of the rate constants for reactions of the carbonate radical with organic and inorganic reductants. INT J CHEM KINET 1991. [DOI: 10.1002/kin.550230606] [Citation(s) in RCA: 47] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
|
18
|
Kinetics and mechanism of the oxidation of thiosulphate by hexachloroplatinate(IV). TRANSIT METAL CHEM 1988. [DOI: 10.1007/bf01087810] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
|
19
|
Dennis C, van Wyk A, Basson S, Leipoldt J. The oxidation of octacyanotungstate(IV) by nitrite ions in acidic medium. Polyhedron 1988. [DOI: 10.1016/s0277-5387(00)81802-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
|
20
|
Kinetics of oxidation of sulphite by hexachloroplatinate(IV) in acidic solution. TRANSIT METAL CHEM 1987. [DOI: 10.1007/bf01171652] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
|
21
|
Olatunji M, Okechukwu RC. Rates and mechanisms of the reactions of octacyanomolybdate(V) anion with L-cysteine, penicillamine and thioglycolic acid in aqueous acidic solutions. Inorganica Chim Acta 1987. [DOI: 10.1016/s0020-1693(00)87912-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
|
22
|
|
23
|
Grases F, Genestar C, Amat E. Mechanisms of homogeneous redox reactions with participation of technetium and related elements. J Radioanal Nucl Chem 1987. [DOI: 10.1007/bf02060538] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
|
24
|
Abstract
The free-radical chemistry of sulfite oxidation is reviewed. Chemical transformations of organic and biological molecules induced by sulfite oxidation are summarized. The kinetics of the free-radical oxidations of sulfite are discussed, as are the kinetics of the reactions of the sulfite-derived radicals SO3 and the peroxy derivative SO5 with organic compounds.
Collapse
|