High-field EPR Study of the Effect of Chloride on Mn2+ Ions in Frozen Aqueous Solutions

Un, Sun; Sedoud, Arezki

doi:10.1007/s00723-009-0062-y

Cited by 7 publications

(9 citation statements)

References 19 publications

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“…For special cases such as MnSODs and the five-coordinate center in OxdC, 19,20,26 they can be as high as 0.3 cm À1 . Since small complexes have about the same range, from 0.005 cm À1 for [Mn(Imidazole) 4 ] 2+ 18 to 0.093 cm À1 for [MnCl(H 2 O) 5 ] + , 38 the validity of any generalization relating the size of the Mn(II) complexes to their zero-field interactions is not evident. Fig.…”

Section: Discussionmentioning

confidence: 99%

Variations in Mn(ii) speciation among organisms: what makes D. radiodurans different

et al. 2015

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The manganese(II) speciation in intact cells of D. radiodurans, E. coli, S. cerevisiae and Arabidopsis thaliana seeds was measured using high-field electron paramagnetic resonance techniques. The majority of the Mn(II) ions in these organisms were six-coordinate, bound predominately by water, phosphates and nitrogen-based molecules. The relative distribution of the different phosphates in bacteria and S. cerevisiae was the same and dominated by monophosphate monoesters. Mn(II) was also found bound to the phosphate backbone of nucleic acids in these organisms. Phosphate ligation in Arabidopsis seeds was dominated by phytate. The extent of nitrogen ligation in the four organisms was also determined. On average, the Mn(II) in D. radiodurans had the most nitrogen ligands followed by E. coli. This was attributed to higher concentrations of Mn(II) bound to proteins in these species. Although constitutively expressed in all four organisms, MnSOD was only detected in D. radiodurans. As previously reported, D. radiodurans also accumulates a second abundant Mn containing protein species. The high concentration of proteinaceous Mn(II) is a unique feature of D. radiodurans.

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Section: Discussionmentioning

confidence: 99%

Variations in Mn(ii) speciation among organisms: what makes D. radiodurans different

et al. 2015

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“…This is in line with previous papers on MnCl 2 which find that contact ion pairs are favored compared to solvent shared ion pairs: Libus ´and Tiałowska 55 interpreted potentiometric and photometric measurements in terms of inner shell (MnCl(H 2 O) 5 ) + ion pairs and Waizumi et al 56 observed mixedligand chloroaqua octahedral complexes in saturated aqueous MnCl 2 solutions. Beagley et al 37 and Un et al 39 performed EXAFS measurements and electron paramagnetic resonance measurements, respectively, finding contact ion pairs.…”

Section: Ion Pairingmentioning

confidence: 99%

“…31,34,35 Less is known for Mn 2+ . [36][37][38][39][40] While for low concentrations, there is general agreement on the structure of solvated Ni 2+ and Mn 2+ , the tendency to form complexes of manganese and nickel ions with counter halide anions is still not well understood. 20,[27][28][29]31,37 Here, we report a far-infrared (FIR) spectroscopic investigation of the hydration dynamics of Mn 2+ and Ni 2+ with Cl À and Br À as counter anions in aqueous solution using a broadband commercial Bruker Fourier transform infrared (FTIR) instrument.…”

Section: Introductionmentioning

confidence: 99%

The low frequency motions of solvated Mn(ii) and Ni(ii) ions and their halide complexes

Sharma

Böhm

Schwaab

et al. 2014

Phys. Chem. Chem. Phys.

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We have investigated the low frequency (30-350 cm(-1)) spectra of solvated MnCl2, MnBr2, NiCl2, and NiBr2. Using a chemical equilibrium model in combination with principal component analysis, we were able to dissect the spectra into molar extinction coefficients due to the solvated ions and - for MnCl2, MnBr2, and NiCl2- to extract information on the ion pair spectra. The deduced anion spectra (calculated as MnCl2-MnBr2 and NiCl2-NiBr2) are very similar and nearly identical to the anion spectra observed for LaCl3-LaBr3. The differences between the cationic contributions MnCl2-NiCl2 and MnBr2-NiBr2 indicate that the solvated cation spectra can be understood in terms of distinct resonances of the octahedrally solvated cation complex that are red-shifted for Mn(2+) compared to Ni(2+). The description of the full extinction spectra requires the introduction of an additional resonance at a center frequency of around 130 cm(-1) that we tentatively assign to hydration water. Cooperative effects are small and are reflected in a change in the band intensity. However, the center frequencies of the observed modes remain unchanged when exchanging the counter ion. Analysis of the ion pair extinction spectra supports contact ion pair formation for MnBr2 and NiCl2 and MnCl2.

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“…High spin d 5 Mn(II) has a characteristic 6 peak spectrum at room temperature [30,31], whereas high spin d 4 Mn(III) is EPR silent. EPR analysis of the Mn-putrebactin reaction solution gave a weak 6 line signal (Figure 3), which matches the control EPR spectrum for aqueous Mn(II).…”

Section: Magnetic Susceptibility Of Mn(iii) Complexes Of Dfob Dfoe Amentioning

confidence: 99%

Magnetic susceptibility of Mn(III) complexes of hydroxamate siderophores

Springer

Butler

2015

Journal of Inorganic Biochemistry

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ABSTRACT:The hydroxamate siderophores putrebactin, desferrioxamine B, and desferrioxamine E bind Mn(II) and promote the air oxidation of Mn(II) to Mn(III) at pH >7.1.The magnetic susceptibility of the manganese complexes were determined by the Evans method and the stoichiometry was probed with electrospray ionization mass spectrometry (ESIMS). The room temperature magnetic moments (µ eff ) for the manganese complexes of desferrioxamines B and E were 4.85 BM and 4.84 BM, respectively, consistent with a high spin,

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High-field EPR Study of the Effect of Chloride on Mn2+ Ions in Frozen Aqueous Solutions

Cited by 7 publications

References 19 publications

Variations in Mn(ii) speciation among organisms: what makes D. radiodurans different

Variations in Mn(ii) speciation among organisms: what makes D. radiodurans different

The low frequency motions of solvated Mn(ii) and Ni(ii) ions and their halide complexes

Magnetic susceptibility of Mn(III) complexes of hydroxamate siderophores

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