High-field EPR investigation of a series of mononuclear Mn(II) complexes doped into Zn(II) hosts

Duboc, Carole; Phoeung, Thida; Jouvenot, Damien; Blackman, Allan G.; McClintock, Lisa F.; Pécaut, Jacques; Collomb, Marie‐Noëlle; Deronzier, Alain

doi:10.1016/j.poly.2007.07.030

Cited by 20 publications

(14 citation statements)

References 25 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The geometry around Zn(II) in the binding site is consistent with reported [Zn 2+ (TPA)] complexes with near‐ideal trigonal bipyramidal geometry (the Zn(II) lies 0.366 Å above the plane of nitrogens). The Zn−N bond lengths are typical, with an average Zn−PyN bond length of 2.05 Å, and an average propeller twist of 24° (N−Zn−N−C) .…”

Section: Resultssupporting

confidence: 87%

Molecular Recognition by Zn(II)‐Capped Dynamic Foldamers

et al. 2020

View full text Add to dashboard Cite

Two α‐aminoisobutyric acid (Aib) foldamers bearing Zn(II)‐chelating N‐termini have been synthesized and compared with a reported Aib foldamer that has a bis(quinolinyl)/mono(pyridyl) cap (BQPA group). Replacement of the quinolinyl arms of the BQPA‐capped foldamer with pyridyl gave a BPPA‐capped foldamer, then further replacement of the linking pyridyl with a 1,2,3‐triazole gave a BPTA‐capped foldamer. Their ability to relay chiral information from carboxylate bound to Zn(II) at the N‐terminus to a glycinamide‐based NMR reporter of conformational preference at the C‐terminus was measured. The importance of the quinolinyl arms became readily apparent, as the foldamers with pyridyl arms were unable to report on the presence of chiral carboxylate in acetonitrile. Low solubility, X‐ray crystallography and 1H NMR spectroscopy suggested that interfoldamer interactions inhibited carboxylate binding. However changing solvent to methanol revealed that the end‐to‐end relay of chiral information could be observed for the Zn(II) complex of the BPTA‐capped foldamer at low temperature.

show abstract

Section: Resultssupporting

confidence: 87%

Molecular Recognition by Zn(II)‐Capped Dynamic Foldamers

et al. 2020

View full text Add to dashboard Cite

show abstract

“…The complexity of the spectra originates not only from the hyperfine interaction, but also from the second‐order contributions of the zfs, which lead to the detection of more than the expected six transitions 2b. 4c–e, 8, 12 The simulation of the HF‐spectra recorded at different frequencies reveals a significant discrepancy between both D values (−0.042 and −0.058 cm −1 as a neat powder and magnetically diluted, respectively). During the preparation of this manuscript, HF‐EPR spectra (powder and in solution) of 3 have been published 5g.…”

Section: Results and Analysismentioning

confidence: 99%

Definition of Magneto‐Structural Correlations for the Mn^II Ion

Duboc

Collomb

Pécaut

et al. 2008

Chemistry A European J

Self Cite

View full text Add to dashboard Cite

The electronic properties of the high spin mononuclear MnII complexes [Mn(tpa)(NCS)2] (1) (tpa=tris-2-picolylamine), [Mn(tBu3-terpy)2](PF6)2 (2) (tBu3-terpy=4,4',4''-tri-tert-butyl-2,2':6',2''-terpyridine) and [Mn(terpy)2](I)2 (3) (terpy=2,2':6',2''-terpyridine) with an N6 coordination sphere have been determined by multifrequency EPR spectroscopy. The X-ray structures of 1.CH3CN and 2.C4H10 O.0.5 C2H5OH.0.5 CH3OH reveal that the MnII ion lies at the center of a distorted octahedron. The D-values of 1-3 all fall in the narrow range of 0.041 to 0.105 cm(-1). The comparison of the results reported here and those found in the literature is consistent with the following observation: the D value is sensitive to the coordination number (6 or 5) of the MnII ion as long as the coordination sphere involves only nitrogen and/or oxygen based ligands. This magneto-structural correlation has been analyzed in this work though DFT model calculations. The zero-field splitting (zfs) parameters of 1-3 have been calculated and are in reasonable agreement with the experimental values. Hypothetical simplified models [Mn(NH3)x(OH2)y]2+ (x+y=5 or 6 and [Mn(NH3)5X]+ (X=OH, Cl)) have been constructed to investigate the origin of the zfs. This investigation reveals i) that D is sensitive to the coordination number (5 or 6) of the MnII ion, ii) for the five coordinate systems the major contribution to D is the spin-orbit coupling part, iii) for the six coordinate systems the major contribution to D is the spin-spin interaction and iv) the deprotonation of a water ligand leads to an increase of D, consistent with the relative ligand fields of OH(-) versus H2O.

show abstract

“…Then, phen (0.12 mmol, 0.046 g) dissolved in CH 3 CN (10 mL) was added to the previous solution. After 20 [Mn(bpy)(…”

Section: Synthesismentioning

confidence: 99%

“…14 For example, the ZFS for Mn II ions is larger when it is bonded to halide ligands. 13,[15][16][17][18][19][20][21][22] It also depends on the coordination number, since pentacoordinated ions display greater axial ZFS parameters (|D| = 0.25-0.30 cm −1 ) than hexacoordinated ones (|D| = 0.0008-0.1750 cm −1 ). 23,24 Moreover, the ZFS parameters could also be affected by the ratio between the N-and O-based ligands.…”

Section: Introductionmentioning

confidence: 99%

Determination of ZFS parameters from the EPR spectra of mono-, di- and trinuclear Mn^IIcomplexes: impact of magnetic coupling

et al. 2017

View full text Add to dashboard Cite

A family of new Mn compounds, consisting of seven dinuclear, three mononuclear, and four trinuclear ones, were synthesised using benzoic acid derivatives n-RCHCOOH, where n-R = 2-MeO, 3-MeO, 4-MeO, or 4-Bu, and 2,2'-bipyridine (bpy) or 1,10-phenantroline (phen) as blocking ligands. The crystal structures of nine of these compounds and the magnetic studies of all of them are reported here. Each type of compound was formed depending on the presence or absence of ClO ions, the solvent used, and/or the presence of a small amount of water in the reaction medium. The use of the tert-buthylbenzoate ligand gave unexpected results, very likely due to the steric hindrance caused by the voluminous Bu groups. The EPR spectra of each type of compound give some peculiar features that allow its identification. Attempts to fit these spectra have been made in order to determine the ZFS parameters, D and E, of the Mn ion (for mononuclear and dinuclear systems) or of the ground state (for trinuclear systems). For trinuclear systems, the single-ion ZFS parameters estimated from those of the ground state provided a good simulation of the EPR spectra of these compounds. The EPR signals observed in each case have been rationalised according to the energy level distribution and the plausible population in the excited states. In some particular situations, the sign of D could be determined from the fit of the EPR spectra of the antiferromagnetic dinuclear compounds, the source of the difference between the spectra lying in the second excited state.

show abstract

High-field EPR investigation of a series of mononuclear Mn(II) complexes doped into Zn(II) hosts

Cited by 20 publications

References 25 publications

Molecular Recognition by Zn(II)‐Capped Dynamic Foldamers

Molecular Recognition by Zn(II)‐Capped Dynamic Foldamers

Definition of Magneto‐Structural Correlations for the Mn^II Ion

Determination of ZFS parameters from the EPR spectra of mono-, di- and trinuclear Mn^IIcomplexes: impact of magnetic coupling

Contact Info

Product

Resources

About

High-field EPR investigation of a series of mononuclear Mn(II) complexes doped into Zn(II) hosts

Cited by 20 publications

References 25 publications

Molecular Recognition by Zn(II)‐Capped Dynamic Foldamers

Molecular Recognition by Zn(II)‐Capped Dynamic Foldamers

Definition of Magneto‐Structural Correlations for the MnII Ion

Determination of ZFS parameters from the EPR spectra of mono-, di- and trinuclear MnIIcomplexes: impact of magnetic coupling

Contact Info

Product

Resources

About

Definition of Magneto‐Structural Correlations for the Mn^II Ion

Determination of ZFS parameters from the EPR spectra of mono-, di- and trinuclear Mn^IIcomplexes: impact of magnetic coupling