Paramagnetic NMR in solution and the solid state

Pell, Andrew J.; Pintacuda, Guido; Grey, Clare P.

doi:10.1016/j.pnmrs.2018.05.001

Cited by 345 publications

(549 citation statements)

References 489 publications

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“…[17][18][19][20] Solid state NMR has been reported to be helpful for studying paramagnetic systems. [21][22][23][24][25][26] Especially, the distribution of paramagnetic dopants can be investigated by the spin-lattice relaxation time, [27][28][29][30] hyperfine shifts [31,32] and the line-broadening effect. [27,33,34] Homogeneous distributions of Tb 3 + and Eu 3 + were shown to be correlated to NMR line broadening and positively related to the brightness of phosphors.…”

Section: Articlesmentioning

confidence: 99%

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A Guide to Brighter Phosphors‐Linking Luminescence Properties to Doping Homogeneity Probed by NMR

Adlung

Zhang

et al. 2019

ChemPhysChem

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Crystalline powders of Ln3+ doped LaPO4 (Ln=Nd, Gd, Dy, Ho, Er, Tm, Yb) have been synthesized to serve in a case study for linking doping homogeneity as determined by NMR to luminescent properties. Samples obtained via different synthesis methods act as examples of homo‐ and inhomogeneous doping. The sample quality was verified by X‐ray diffraction. The homogeneously doped samples show improved luminescent properties in terms of brightness and lifetime which is consistent with the interpretation that, NMR visibility curves probe the distribution of paramagnetic dopants on a similar length scale as necessary for an efficient energy transfer in crystalline phosphors i. e. between sensitizers and activators, and to killer sites. Thus “NMR homogeneity” as observed by visibility curves may serve as a tool to optimize luminescent materials.

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Section: Articlesmentioning

confidence: 99%

“…Solid state NMR has been reported to be helpful for studying paramagnetic systems . Especially, the distribution of paramagnetic dopants can be investigated by the spin‐lattice relaxation time, hyperfine shifts and the line‐broadening effect .…”

Section: Introductionmentioning

confidence: 99%

A Guide to Brighter Phosphors‐Linking Luminescence Properties to Doping Homogeneity Probed by NMR

Adlung

Zhang

et al. 2019

ChemPhysChem

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“…[27,32] It is worth noting that, according to Equation (5), the sign of the NMR Fermi-contact term provides a straightforward access to the sign of the spin-density at the probed nuclei. This formula is valid when only one spin state is populated, and when the ground state can be described by as pin quantum number, S. From there, the d FC can be easily connected to the spin-density located in the "ith" so rbitals, 1 is r ðÞ .…”

Section: Spin-densityf Rom Nmr Spectroscopy Measurementsmentioning

confidence: 99%

“…The rationalization of these macroscopic magnetic properties is then commonlya ddressed by phenomenological approaches based on spin Hamiltonian models. Examples can be found for numerous kinds of paramagnetics ystems, including lanthanide-based compounds, [24][25][26] or solid-state materials [27] such as lithium ion batteries. However,the analysis of the EPR data relies on effective Hamiltonian (g-tensors and/ or zero-field splitting parameters).…”

Section: Introductionmentioning

confidence: 99%

Probing the Local Magnetic Structure of the [Fe^III(Tp)(CN)₃]⁻ Building Block Via Solid‐State NMR Spectroscopy, Polarized Neutron Diffraction, and First‐Principle Calculations

Flambard

Garnier

et al. 2019

Chemistry A European J

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The local magnetic structure in the [Fe III (Tp)(CN) 3 ] À building block was investigated by combining paramagnetic Nuclear Magnetic Resonance (pNMR) spectroscopy and polarized neutrond iffraction (PND) with first-principle calculations. The use of the pNMR and PND experimental techniques revealed the extension of spin-density from the metal to the ligands, as well as the different spin mechanisms that take place in the cyanidol igands: Spin-polarization on the carbon atomsa nd spin-delocalization on the nitrogen atoms.T he resultso fo ur combined density functional theory (DFT) and multireference calculations were found in good agreementw ith the PND results and the experimen-tal NMR chemical shifts. Moreover,t he ab-initio calculations allowedu st oc onnectt he experimental spin-density map characterized by PNDa nd the suggested distribution of the spin-density on the ligandso bserved by NMR spectroscopy. Interestingly,s ignificant differences were observed between the pseudo-contact contributions of the chemical shifts obtained by theoretical calculations and the values derived from NMR spectroscopy using as imple point-dipole model. These discrepancies underline the limitation of the pointdipole model and the need for more elaborate approaches to break down the experimental pNMR chemical shifts into contacta nd pseudo-contact contributions.Supporting information and the ORCID identification number(s) for the author(s) of this articlecan be found under: https://doi.org/10.1002/chem.201902239.A dditional data regarding the experimental and computational details,experimental NMR data for the diamagnetic reference and the paramagnetic complex, crystal structure data for the diamagnetic reference and the magnetization characterization:DFT spin-densities, NLMOs, g-factors, and HyFCCs for [Fe III (Tp)(CN) 3 ] À .Additional calculated NMR shielding constants and chemical shifts.

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“…The 19 F probes based on Ln 3+ ions investigated to date were designed for the paramagnetic ions of the second part of the lanthanide series (Tb 3+ to Yb 3+ ). These Ln 3+ ions combine a high effective magnetic moment and relatively long relaxation times of the electron spin, which prevents extensive line broadening . The detailed work of Parker and co‐workers indicated that for these metal ions the optimal distance between the paramagnetic ion and the 19 F nuclei should be in the range 5–7 Å .…”

Section: Introductionmentioning

confidence: 99%

Gadolinium(III)‐Based Dual ¹H/¹⁹F Magnetic Resonance Imaging Probes

Pujales‐Paradela

Savić

Esteban‐Gómez

et al. 2019

Chemistry A European J

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We present two novel octadentate cyclen‐based ligands bearing one (L1) or two (L2) phenylacetamide pendants with two CF3 groups either at positions 3 and 5 (L1) or 4 (L2). The corresponding Gd3+ complexes possess one coordinated water molecule, as confirmed by luminescence lifetime measurements on the EuIII and TbIII analogues. A detailed 1H and 17O relaxometric characterization has revealed the parameters that govern the relaxivities of these complexes. The water‐exchange rate of the mono‐amide derivative GdL1 (kex298=1.52×106 s−1) is faster than that determined for the bis‐amide complex GdL2 (kex298=0.73×106 s−1). 1H and 19F NMR studies have indicated that the complexes are present in solution almost exclusively as the square‐antiprismatic (SAP) isomers. 19F NMR relaxation studies indicated Gd⋅⋅⋅F distances of 7.4±0.1 and 9.1±0.1 Å for GdL1 and GdL2, respectively. Phantom MRI studies revealed the favorable properties of GdL2 as a dual 1H/19F magnetic resonance imaging (MRI) probe, whereas the shorter Gd⋅⋅⋅F distance of GdL1 reduces the signal‐to‐noise ratio due to the very short transverse relaxation time of the 19F NMR signal.

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Paramagnetic NMR in solution and the solid state

Cited by 345 publications

References 489 publications

A Guide to Brighter Phosphors‐Linking Luminescence Properties to Doping Homogeneity Probed by NMR

A Guide to Brighter Phosphors‐Linking Luminescence Properties to Doping Homogeneity Probed by NMR

Probing the Local Magnetic Structure of the [Fe^III(Tp)(CN)₃]⁻ Building Block Via Solid‐State NMR Spectroscopy, Polarized Neutron Diffraction, and First‐Principle Calculations

Gadolinium(III)‐Based Dual ¹H/¹⁹F Magnetic Resonance Imaging Probes

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Paramagnetic NMR in solution and the solid state

Cited by 345 publications

References 489 publications

A Guide to Brighter Phosphors‐Linking Luminescence Properties to Doping Homogeneity Probed by NMR

A Guide to Brighter Phosphors‐Linking Luminescence Properties to Doping Homogeneity Probed by NMR

Probing the Local Magnetic Structure of the [FeIII(Tp)(CN)3]− Building Block Via Solid‐State NMR Spectroscopy, Polarized Neutron Diffraction, and First‐Principle Calculations

Gadolinium(III)‐Based Dual 1H/19F Magnetic Resonance Imaging Probes

Contact Info

Product

Resources

About

Probing the Local Magnetic Structure of the [Fe^III(Tp)(CN)₃]⁻ Building Block Via Solid‐State NMR Spectroscopy, Polarized Neutron Diffraction, and First‐Principle Calculations

Gadolinium(III)‐Based Dual ¹H/¹⁹F Magnetic Resonance Imaging Probes