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Bertin D, Gigmes D, Marque SRA, Siri D, Tordo P, Trappo G. Effect of the Carboxylate Salt on the CON Bond Homolysis of SG1-Based Alkoxyamines. Chemphyschem 2008; 9:272-81. [DOI: 10.1002/cphc.200700481] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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77
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Bardelang D, Charles L, Finet JP, Jicsinszky L, Karoui H, Marque SRA, Monnier V, Rockenbauer A, Rosas R, Tordo P. Alpha-phenyl-N-tert-butylnitrone-type derivatives bound to beta-cyclodextrins: syntheses, thermokinetics of self-inclusion and application to superoxide spin-trapping. Chemistry 2008; 13:9344-54. [PMID: 17729216 DOI: 10.1002/chem.200700369] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
alpha-Phenyl-N-tert-butylnitrone (PBN) derivatives bound to beta-cyclodextrin derivatives have been synthesized. Inclusion of the PBN group into the beta-cyclodextrin moiety is host- and temperature-dependent. In the case of the nitrone linked to permethylated cyclodextrin (Me3CD-PBN), the thermokinetic parameters are in favour of a slow chemical exchange between a tight and a loose complex. In contrast, 2,6-di-O-Me-beta-cyclodextrin-grafted PBN (Me2CD-PBN) exists either in a fast exchange or as a strongly self-associated complex. The covalent cyclodextrin-PBN compounds have been used to trap carbon and oxygen-centred free radicals. The self-associated forms of the beta-CD-spin-traps are compatible with effective spin-trapping, affording spin-adducts with enhanced EPR signal intensities relative to noncovalent CD-nitrone systems or the nitrone alone. This kind of cyclodextrin-bound nitrone is the first type of covalent supramolecular spin-trap and should open new possibilities for the study of biological free radicals in vivo.
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Bertin D, Dufils PE, Durand I, Gigmes D, Giovanetti B, Guillaneuf Y, Marque SRA, Phan T, Tordo P. Effect of the Penultimate Unit on the CON Bond Homolysis in SG1-Based Alkoxyamines. MACROMOL CHEM PHYS 2008. [DOI: 10.1002/macp.200700441] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Chalier F, Hardy M, Ouari O, Rockenbauer A, Tordo P. Design of New Derivatives of Nitrone DEPMPO Functionalized at C-4 for Further Specific Applications in Superoxide Radical Detection. J Org Chem 2007; 72:7886-92. [PMID: 17880238 DOI: 10.1021/jo071070s] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A general synthetic route to prepare derivatives of the DEPMPO nitrone (5-diethoxyphosphoryl-5-methyl-1-pyrroline-N-oxide) functionalized at C-4 was established via the synthesis of 4-HMDEPMPO nitrone (5-diethoxyphosphoryl-4-hydroxymethyl-5-methyl-1-pyrroline-N-oxide) that was obtained from reduction of the nitro compound 1. (4R*,5S*)-4-HMDEPMPO was successfully separated from its minor diastereoisomer and could be used to generate various substituted analogues. Among them, 4-NHSDEPMPO, 5-diethoxyphosphoryl-4-succinimidyloxycarbonyloxymethyl-5-methyl-1-pyrroline-N-oxide, constitutes a NH2-reactive precursor for further conjugation to relevant moieties such as targeting groups, labels, or drugs. From 4-NHSDEPMPO, a biotinylated nitrone was synthesized offering new perspectives for targeted delivery applications. A short study of the trapping behaviors of the (4R*,5S*)-isomer of these 4-HMDEPMPO analogues proved that they are as good as DEPMPO for detecting superoxide. For each isomer, only one diastereoisomer adduct was obtained, resulting from the addition of superoxide on the less hindered face of the nitrone, that is, trans to the phosphoryl group and the C-4 substituent. From spectra simulation and experiments in various solvents, we proved that ESR patterns of each adduct corresponded to the superimposed signals of two sets of conformers in a sufficiently slow chemical exchange to induce a widening and a dissymmetry of some of the signal lines. This phenomenon was drastically reduced when compared with that observed for DEPMPO superoxide and attributed to a similar chemical exchange, and it did not hamper spectrum assignment. Determination of the decay rate of the superoxide adduct of (4R*,5S*)-4-HMDEPMPO proved that it has a 25% longer half-life time than the superoxide adduct of DEPMPO.
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Dufils PE, Chagneux N, Gigmes D, Trimaille T, Marque SR, Bertin D, Tordo P. Intermolecular radical addition of alkoxyamines onto olefins: An easy access to advanced macromolecular architectures precursors. POLYMER 2007. [DOI: 10.1016/j.polymer.2007.06.050] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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81
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Hardy M, Rockenbauer A, Vásquez-Vivar J, Felix C, Lopez M, Srinivasan S, Avadhani N, Tordo P, Kalyanaraman B. Detection, characterization, and decay kinetics of ROS and thiyl adducts of mito-DEPMPO spin trap. Chem Res Toxicol 2007; 20:1053-60. [PMID: 17559235 PMCID: PMC4455887 DOI: 10.1021/tx700101d] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
We report here the detection and characterization of spin adducts formed from the trapping of reactive oxygen species (superoxide and hydroxyl radicals) and glutathiyl and carbon-centered radicals by a newly synthesized nitrone, Mito-DEPMPO. This is a cationic nitrone spin trap with a triphenyl phosphonium cation conjugated to the DEPMPO analogue. The Mito-DEPMPO-OOH adduct, formed from the trapping of superoxide by Mito-DEPMPO, was enzymatically generated using xanthine/xanthine oxidase and neuronal nitric oxide synthase, and chemically generated by KO2 in 18-crown-6. The Mito-DEPMPO-OOH adduct exhibits an eight-line EPR spectrum with partial asymmetry arising from the alternate line-width effect. The half-life of the Mito-DEPMPO-OOH adduct is 2-2.5-times greater than that of the DEPMPO-OOH. The Mito-DEPMPO-SG adduct, formed from the trapping of glutathiyl radicals by Mito-DEPMPO, is 3-times more persistent than the analogue DEPMPO-SG adduct. In this study, we describe the EPR characterization of spin adducts formed from Mito-DEPMPO. The EPR parameters of Mito-DEPMPO adducts are distinctly different and highly characteristic. The detection of superoxide from an intact mitochondrion was feasible with Mito-DEPMPO but not with DEPMPO. We conclude that Mito-DEPMPO nitrone and its analogues are more effective than most nitrone spin traps for trapping superoxide, hydroxyl, and thiyl radicals formed in biological systems, including mitochondria.
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Bertin D, Grimaldi S, Leblanc M, Marque SR, Siri D, Tordo P. A DFT study of the hydrogen atom abstraction from 2,4,6-trimethylheptane: A model of peroxidic degradation for syndio polypropylene. ACTA ACUST UNITED AC 2007. [DOI: 10.1016/j.theochem.2007.03.008] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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83
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Rockenbauer A, Clément JL, Culcasi M, Mercier A, Tordo P, Pietri S. Combined ESR and thermodynamic studies of the superoxide adduct of 5-(diethoxyphosphoryl)-5-methyl-1-pyrroline N-oxide (DEPMPO): hindered rotation around the O-O bond evidenced by two-dimensional simulation of temperature-dependent spectra. J Phys Chem A 2007; 111:4950-7. [PMID: 17518450 DOI: 10.1021/jp070679u] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Experiments were performed to elucidate the origin of the superhyperfine structure and line width alternation (LWA) seen in the ESR spectrum of the major diastereoisomer (1) of DEPMPO-OOH, the remarkably persistent superoxide adduct of 5-(diethoxyphosphoryl)-5-methyl-1-pyrroline N-oxide (DEPMPO). Using selectively deuterated DEPMPO derivatives, we demonstrated that the superhyperfine pattern can be unambiguously attributed to long-range couplings. The recording in pyridine of highly resolved spectra in a wide temperature range, combined with two-dimensional simulation, allowed us to characterize an inverted LWA in 1 and revealed a uniform line broadening in the spectrum of the minor DEPMPO-OOH diastereoisomer (2), with both effects originating from a chemical exchange between conformers. When the individual spectra of 1 presenting LWA in the fast-exchange regime were simulated, four equally good fits were obtained and this ambiguity could be resolved by using a two-dimensional simulation technique. The thermodynamic and kinetic constants of this exchange were consistent with a rotation around the O-O bond. We propose that line broadening effects in 1 and 2 result from this O-O rotation concerted with the pseudo-rotation of the pyrrolidine ring.
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Guillaneuf Y, Gigmes D, Marque SRA, Astolfi P, Greci L, Tordo P, Bertin D. First Effective Nitroxide-Mediated Polymerization of Methyl Methacrylate. Macromolecules 2007. [DOI: 10.1021/ma062330v] [Citation(s) in RCA: 147] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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85
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Tordo P. Spin-trapping: Recent developmetns and applications. ELECTRON PARAMAGNETIC RESONANCE 2007. [DOI: 10.1039/9781847553539-00116] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
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Tordo P, Boyer M, Cerri V, Vila F. E.P.R. STUDY OF THE ACTION OF NITROSO DERIVATIVES ON ORGANOPHOSPHORUS COMPOUNDS. II1—CASE OF 2-METHYL, 2-NITROSOPROPANE (M.N.P.). ACTA ACUST UNITED AC 2007. [DOI: 10.1080/03086647708079950] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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88
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Hardy M, Chalier F, Ouari O, Finet JP, Rockenbauer A, Kalyanaraman B, Tordo P. Mito-DEPMPO synthesized from a novel NH2-reactive DEPMPO spin trap: a new and improved trap for the detection of superoxide. Chem Commun (Camb) 2007:1083-5. [PMID: 17325813 DOI: 10.1039/b616076j] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Mito-DEPMPO, a new DEPMPO analogue bearing a triphenylphosphonium group, was synthesized via a novel NH2-reactive DEPMPO. The half-life of the Mito-DEPMPO superoxide adduct was estimated to be ca. 40 min. Using Mito-DEPMPO, reactive oxygen species generated in intact mitochondria were detected and characterized by EPR.
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Amedjkouh M, Faure R, Hatem J, Tordo P, Grimaldi J. SYNTHESIS AND CYCLIZATION OF PHOSPHORYLATED β-ALLENIC AMINES. PHOSPHORUS SULFUR 2006. [DOI: 10.1080/10426509708043545] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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90
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Redouane N, Vila F, Chalier F, Gronchi G, Tordo P. Triarylphosphines : Molecular Geometry, Anodic Behavior and ESR Study of the Radical Cations. PHOSPHORUS SULFUR 2006. [DOI: 10.1080/10426509308045629] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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91
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Roubaud V, Bliek C, Lauricella R, Vila F, Siri D, Tordo P. CONFORMATIONAL ANALYSIS OF DIALKYL (2,5-DIALKYL PYRROLIDIN-2-YL)PHOSPHONATES AND DIETHYL(2,5,5-TRIMETHYL PYRROLIDIN-2-YL)PHOSPHONATE BY X-RAY ANALYSIS, NMR AND FORCE FIELD CALCULATIONS. PHOSPHORUS SULFUR 2006. [DOI: 10.1080/10426509608046358] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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92
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Acerbis S, Bertin D, Boutevin B, Gigmes D, Lacroix-Desmazes P, Le Mercier C, Lutz JF, Marque S, Siri D, Tordo P. Intramolecular Hydrogen Bonding: The Case ofβ-Phosphorylated Nitroxide (= Aminoxyl) Radical. Helv Chim Acta 2006. [DOI: 10.1002/hlca.200690201] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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93
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Gigmes D, Gaudel-Siri A, Marque S, Bertin D, Tordo P, Astolfi P, Greci L, Rizzoli C. Alkoxyamines of Stable Aromatic Nitroxides: NOvs. CO Bond Homolysis. Helv Chim Acta 2006. [DOI: 10.1002/hlca.200690215] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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94
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Zeghdaoui A, Benali-Cherif N, Finet JP, Tordo P. UNEXPECTED REACTION OF TRIS(TRIMETHYLSILYL)PHOSPHITE WITH A HINDERED NITRONE. PHOSPHORUS SULFUR 2006. [DOI: 10.1080/10426509408021948] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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95
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Berchadsky Y, Bernard-Henriet C, Finet JP, Lauricella R, Marque SRA, Tordo P. Persilylated phosphoranyl radicals: the first persistent noncyclic phosphoranyl radicals. Chemistry 2006; 12:7084-94. [PMID: 16847992 DOI: 10.1002/chem.200600299] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Persistent noncyclic phosphoranyl radicals have been prepared and observed by electron paramagnetic resonance (EPR) for the first time. They were obtained by UV-photolysis of a solution containing a bis(trialkylsilyl) peroxide (R = Me, Et) and a tris(trialkylsilyl) phosphite (R = Me, Et, iPr). EPR parameters (a(P) approximately 100 mT) are typical of phosphoranyl radicals exhibiting a trigonal-bipyramidal structure, with the odd electron in an equatorial site. Analysis of the pseudo-first-order decay shows that these phosphoranyl radicals decay by S(H)2 homolytic substitution on the bis(trialkylsilyl) peroxide and by loss of a trialkylsilyloxyl radical (alpha-scission reaction). Both the S(H)2 and alpha-scission reactions depend on the steric bulk of the alkyl groups, that is, the bulkier the alkyl group, the slower the S(H)2 and alpha-scission reactions.
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Chauvin F, Couturier JL, Dufils PE, Gérard P, Gigmes D, Guerret O, Guillaneuf Y, Marque SRA, Bertin D, Tordo P. Crowded Phosphonylated Alkoxyamines with Low Dissociation Temperatures: A Milestone in Nitroxide-Mediated Polymerization. ACS SYMPOSIUM SERIES 2006. [DOI: 10.1021/bk-2006-0944.ch023] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
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97
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Bardelang D, Rockenbauer A, Jicsinszky L, Finet JP, Karoui H, Lambert S, Marque SRA, Tordo P. Nitroxide Bound β-Cyclodextrin: Is There an Inclusion Complex? J Org Chem 2006; 71:7657-67. [PMID: 16995671 DOI: 10.1021/jo061194p] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
236CDTIPNO, a derivative of the persistent free radical TIPNO (1,1-dimethylethyl 2-methyl-1-phenylpropyl nitroxide) covalently bound to a permethylated-beta-cyclodextrin, was prepared. Self-association of 236CDTIPNO in water was proved by solvent- and competition-dependent EPR spectroscopy experiments with 2,6-di-O-Me-beta-cyclodextrin (DIMEB) and permethylated-beta-cyclodextrin (TRIMEB) as external hosts competing for accommodation of the TIPNO moiety. Temperature-dependent EPR spectra were simulated with a novel two-dimensional (field-temperature) EPR simulation program that afforded a full determination of the thermodynamic parameters characterizing the rate constants of the self-inclusion reaction derived from Arrhenius and Eyring models. This method allows separating the line broadening effects due to relaxation from a chemical exchange, even if only the fast exchange regime is accessible experimentally. The activation parameters for the forward and backward steps were consistent with an equilibrium between a nonassociated form and a weakly associated form, with activation free enthalpies for each reaction of around 34 kJ.mol(-)(1).
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Guillaneuf Y, Gigmes D, Marque SRA, Tordo P, Bertin D. Nitroxide-Mediated Polymerization of Methyl Methacrylate Using an SG1-Based Alkoxyamine: How the Penultimate Effect Could Lead to Uncontrolled and Unliving Polymerization. MACROMOL CHEM PHYS 2006. [DOI: 10.1002/macp.200600125] [Citation(s) in RCA: 104] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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99
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Rockenbauer A, Nagy NV, Le Moigne F, Gigmes D, Tordo P. Thermodynamic Analysis of the Chemical Exchange of β−Phosphorylated Cyclic Nitroxides by Using Two-dimensional (Temperature versus Magnetic Field) Simulation of ESR Spectra: The Impact of Labile Solvent−Solute Interactions on Molecular Dynamics. J Phys Chem A 2006; 110:9542-8. [PMID: 16884186 DOI: 10.1021/jp0612331] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
A complete thermodynamic characterization of the chair-to-chair interconversion in beta-diphosphorylated piperidine-N-oxyl radicals was achieved by means of the analysis of temperature-dependent ESR spectra. A new two-dimensional simulation method was developed with the coordinates temperature and magnetic field, in which the entire set of spectra was simulated simultaneously by adjusting the coefficients in the power expansion, giving the temperature-dependent ESR parameters and the thermodynamic and kinetic parameters determining the site populations and exchange rates, respectively. The new method promotes elimination of the ambiguities inherent in the spectroscopic determination of thermodynamic parameters. Labile solvent-solute interactions can strongly influence the chemical exchange, producing a complex network of symmetric and asymmetric interconversions. The solvent dependence of magnetic relaxation was also analyzed.
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Chauvin F, Dufils PE, Gigmes D, Guillaneuf Y, Marque SRA, Tordo P, Bertin D. Nitroxide-Mediated Polymerization: The Pivotal Role of the kd Value of the Initiating Alkoxyamine and the Importance of the Experimental Conditions. Macromolecules 2006. [DOI: 10.1021/ma0527193] [Citation(s) in RCA: 155] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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