Improved syntheses, structures, spectral and electrochemical properties of [Mn2III(µ-O)(µ-O2CMe)2L2]2+and [Mn2IV(µ-O)3L2]2+complexes. Two homologous series derived from eight N-substituted 1,4,7-triazacyclononanes

Koek, J. H.; Russell, Stephen W.; Wolf, Lodewijk van der; Hage, Ronald; Warnaar, Johann B.; Spek, Anthony L.; Kerschner, Judy; DelPizzo, Lisa

doi:10.1039/dt9960000353

Cited by 51 publications

(27 citation statements)

References 42 publications

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“…For the synthesis and properties of catalyst 1, see [39,40]. Aqueous 70% solution of hydrogen peroxide (compound 2; Peróxidos do Brasil), (+)-carvone (compound 3; Fluka; content ≥ 99.0 %), and oxalic acid (compound 4; Fluka) were used as received.…”

Section: Methodsmentioning

confidence: 99%

Carvone epoxidation by system “hydrogen peroxide-[Mn2L2O3][PF6]2 (L = 1,4,7-trimethyl-1,4,7-triazacyclononane)-carboxylic acid”: a combinatorial approach to the process optimization

Mandelli

Steffen

Shul'pin

2006

React Kinet Catal Lett

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Epoxidation of natural terpene (+)-carvone by the system consisting of a catalyst, oxalic acid (co-catalyst) and H 2 O 2 (70% aqueous solution; oxidant) was studied and factorial design methods were applied for the optimization of this reaction. A dinuclear manganese(IV) complex [LMn(O) 3 MnL](PF 6 ) 2 (L = 1,4,7-trimethyl-1,4,7-triazacyclononane) was used as a catalyst, and acetonitrile was employed as a solvent. An analysis by methods of the complete 2 4 factorial design showed that an increase in the catalyst concentration gives a strong positive effect on the carvone conversion and selectivity. Hydrogen peroxide has a smaller positive effect on the conversion, but at high concentration, H 2 O 2 leads to some decrease in the selectivity. An increase in the oxalic acid concentration has a beneficial effect on the conversion, but does not affect the selectivity. **Part 7 of the series "Oxidations by the system hydrogen peroxide-[Mn 2 L 2 O 3 ][PF 6 ] 2 (L = 1,4,7-trimethyl-1,4,7-triazacyclononane)-carboxylic acid". For parts 1-6, see , respectively. The present work was reported at the

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Section: Methodsmentioning

confidence: 99%

Carvone epoxidation by system “hydrogen peroxide-[Mn2L2O3][PF6]2 (L = 1,4,7-trimethyl-1,4,7-triazacyclononane)-carboxylic acid”: a combinatorial approach to the process optimization

Mandelli

Steffen

Shul'pin

2006

React Kinet Catal Lett

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“…These complexes are relatively more stable than the bipyridine or phenanthroline analogues in aqueous solution. Polyazamacrocyclic complexes of manganese have also gathered special attention in relation to study of oxidation states, coordination behavior, and their role as biological catalysts 19–21.…”

Section: Introductionmentioning

confidence: 99%

A comparative kinetic study for the oxidation of 2‐mercaptoethanol by di‐μ‐oxo‐bis(1,4,7,10‐tetraazacyclododecane)‐dimanganese(III,IV) and di‐μ‐oxo‐bis(1,4,8,11‐tetraazacyclotetradecane)‐dimanganese(III,IV) complexes: Influence of copper(II)

Goswami

Shaikh

Panja

et al. 2003

Int J of Chemical Kinetics

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A comparative kinetic study of the reactions of two mixed valence manganese(III,IV) complexes with macrocyclic ligands, [L 1 Mn IV ,4,8,11-tetraazacyclotetradecane) with 2-mercaptoethanol (RSH) has been carried out by spectrophotometry in aqueous buffer at (30 ± 0.1) • C. Rate of the reactions between the oxidants and the reductant was found to be negligibly slow with no systematic dependence on either redox partners. Externally added copper(II) (usually 5 × 10 −7 mol dm −3 ), however, increases the rate of the reduction of 1 and 2 significantly. In the presence of catalytic amount of copper(II), the rate of the reaction is nearly proportional to [RSH] at lower concentration of the reductant but follows a saturation kinetics at higher concentration of the latter for the reaction between 1 and the thiol. Reaction rate was found to be strongly influenced by the variation of acidity of the medium and the observed kinetics suggests that the two reductant species ([Cu(RSH)] 2+ and [Cu(RS)] + ) are significant for the reaction between 1 and the thiol. The dependence of the rate on [RSH] for the reduction of 2 by the thiol was complex and rationalized considering two equilibria involving the catalyst (Cu 2+ ) and the reductant. The pH rate profile suggests that both the µ-O protonated [Mn III (O)(OH)Mn IV ] and the deprotonated [Mn III (O) 2 Mn IV ] forms of the oxidant 2 become important. The kinetic results presented in this study indicate the domination of outer-sphere path.

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“…The flame ionisation detector response factors were obtained after calibration experiments, using a standard substrate mixture. 2+ was synthesised by J. Koek et al [23] by adding one equivalent of a strong acid to the acetonitrile solution of the triazamacrocycle prior to coordination. Presumably the monoprotonation of L-Me 2 preorganises the conformation of the macrocycle suitable for complexation.…”

Section: Catalytic Runsmentioning

confidence: 99%

“…Herein we report a straight-forward synthesis for dinuclear Mn(III)-Mn(III) and Mn(III)-Mn(IV) complexes containing L-Me 2 ligands as well as carboxylatoand oxo-bridges, including the isolation and X-ray characterisation of the postulated [23] 2+ is also reported [23]. The catalytic oxidation properties of these complexes are discussed.…”

Section: Introductionmentioning

confidence: 99%

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Dinuclear manganese complexes containing 1,4-dimethyl-1,4,7-triazacyclononane ligands as well as carboxylato and oxo bridges

Romakh

Therrien

Karmazin-Brelot

et al. 2006

Inorganica Chimica Acta

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Improved syntheses, structures, spectral and electrochemical properties of [Mn₂^III(µ-O)(µ-O₂CMe)₂L₂]²⁺and [Mn₂^IV(µ-O)₃L₂]²⁺complexes. Two homologous series derived from eight N-substituted 1,4,7-triazacyclononanes

Cited by 51 publications

References 42 publications

Carvone epoxidation by system “hydrogen peroxide-[Mn2L2O3][PF6]2 (L = 1,4,7-trimethyl-1,4,7-triazacyclononane)-carboxylic acid”: a combinatorial approach to the process optimization

Carvone epoxidation by system “hydrogen peroxide-[Mn2L2O3][PF6]2 (L = 1,4,7-trimethyl-1,4,7-triazacyclononane)-carboxylic acid”: a combinatorial approach to the process optimization

A comparative kinetic study for the oxidation of 2‐mercaptoethanol by di‐μ‐oxo‐bis(1,4,7,10‐tetraazacyclododecane)‐dimanganese(III,IV) and di‐μ‐oxo‐bis(1,4,8,11‐tetraazacyclotetradecane)‐dimanganese(III,IV) complexes: Influence of copper(II)

Dinuclear manganese complexes containing 1,4-dimethyl-1,4,7-triazacyclononane ligands as well as carboxylato and oxo bridges

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