NMR studies of mixed-ligand lanthanide (III) complexes. Peculiarities of molecular structure, dynamics and paramagnetic properties for cerium subgroup chelates with crown ethers

Sergey P. Babailov, Dmitry A. Mainichev

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10 Citations (Scopus)

Abstract

The molecular structure, dynamics and paramagnetic properties of the complex cations [Ln(ptfa)2 (18-crown-6)]+ in deuterated toluene were studied for Ln = La, Ce, Pr and Nd. The activation enthalpy values of 68 ± 5, 55 ± 15 and 60 ± 13 kJ mol-1 for the 18-crown-6 conformational inversion processes for the complex cations of Ce, Pr and Nd, respectively, were obtained. Quantitative investigation of the lanthanide-induced chemical shifts shows a monotonic change of a spatial structure and magnetic susceptibility in comparison with the Bleaney predicted dependence. The free energy of molecular inversion activation for 18-crown-6 molecules in the complex cation [Ln(fod)2(18-crown-6)]+ is 74 ± 9 kJ mol-1 at 363 K, which is a little more than the value of the free energy of activation 64 ± 9 kJ mol-1 at 363 K in the complex cation [Ln(ptfa)2(18-crown-6)]+.

Original languageEnglish
Pages (from-to)187-193
Number of pages7
JournalJournal of Inclusion Phenomena and Macrocyclic Chemistry
Volume43
Issue number3-4
DOIs
Publication statusPublished - 2002
Externally publishedYes

Fingerprint

cerium
Crown Ethers
Cerium
Lanthanoid Series Elements
rare earth elements
chelates
Molecular Dynamics Simulation
subgroups
Molecular Structure
chemical structure
Molecular structure
ethers
cations
molecular structure
Nuclear magnetic resonance
Cations
Ligands
nuclear magnetic resonance
ligands
activation

Keywords

  • Complexes
  • Crown ethers
  • Dynamic NMR
  • Enthalpy of activation
  • Lanthanides
  • Molecular dynamics

ASJC Scopus subject areas

  • Chemistry(all)
  • Condensed Matter Physics

Cite this

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title = "NMR studies of mixed-ligand lanthanide (III) complexes. Peculiarities of molecular structure, dynamics and paramagnetic properties for cerium subgroup chelates with crown ethers",
abstract = "The molecular structure, dynamics and paramagnetic properties of the complex cations [Ln(ptfa)2 (18-crown-6)]+ in deuterated toluene were studied for Ln = La, Ce, Pr and Nd. The activation enthalpy values of 68 ± 5, 55 ± 15 and 60 ± 13 kJ mol-1 for the 18-crown-6 conformational inversion processes for the complex cations of Ce, Pr and Nd, respectively, were obtained. Quantitative investigation of the lanthanide-induced chemical shifts shows a monotonic change of a spatial structure and magnetic susceptibility in comparison with the Bleaney predicted dependence. The free energy of molecular inversion activation for 18-crown-6 molecules in the complex cation [Ln(fod)2(18-crown-6)]+ is 74 ± 9 kJ mol-1 at 363 K, which is a little more than the value of the free energy of activation 64 ± 9 kJ mol-1 at 363 K in the complex cation [Ln(ptfa)2(18-crown-6)]+.",
keywords = "Complexes, Crown ethers, Dynamic NMR, Enthalpy of activation, Lanthanides, Molecular dynamics",
author = "Babailov, {Sergey P.} and Mainichev, {Dmitry A.}",
year = "2002",
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TY - JOUR

T1 - NMR studies of mixed-ligand lanthanide (III) complexes. Peculiarities of molecular structure, dynamics and paramagnetic properties for cerium subgroup chelates with crown ethers

AU - Babailov, Sergey P.

AU - Mainichev, Dmitry A.

PY - 2002

Y1 - 2002

N2 - The molecular structure, dynamics and paramagnetic properties of the complex cations [Ln(ptfa)2 (18-crown-6)]+ in deuterated toluene were studied for Ln = La, Ce, Pr and Nd. The activation enthalpy values of 68 ± 5, 55 ± 15 and 60 ± 13 kJ mol-1 for the 18-crown-6 conformational inversion processes for the complex cations of Ce, Pr and Nd, respectively, were obtained. Quantitative investigation of the lanthanide-induced chemical shifts shows a monotonic change of a spatial structure and magnetic susceptibility in comparison with the Bleaney predicted dependence. The free energy of molecular inversion activation for 18-crown-6 molecules in the complex cation [Ln(fod)2(18-crown-6)]+ is 74 ± 9 kJ mol-1 at 363 K, which is a little more than the value of the free energy of activation 64 ± 9 kJ mol-1 at 363 K in the complex cation [Ln(ptfa)2(18-crown-6)]+.

AB - The molecular structure, dynamics and paramagnetic properties of the complex cations [Ln(ptfa)2 (18-crown-6)]+ in deuterated toluene were studied for Ln = La, Ce, Pr and Nd. The activation enthalpy values of 68 ± 5, 55 ± 15 and 60 ± 13 kJ mol-1 for the 18-crown-6 conformational inversion processes for the complex cations of Ce, Pr and Nd, respectively, were obtained. Quantitative investigation of the lanthanide-induced chemical shifts shows a monotonic change of a spatial structure and magnetic susceptibility in comparison with the Bleaney predicted dependence. The free energy of molecular inversion activation for 18-crown-6 molecules in the complex cation [Ln(fod)2(18-crown-6)]+ is 74 ± 9 kJ mol-1 at 363 K, which is a little more than the value of the free energy of activation 64 ± 9 kJ mol-1 at 363 K in the complex cation [Ln(ptfa)2(18-crown-6)]+.

KW - Complexes

KW - Crown ethers

KW - Dynamic NMR

KW - Enthalpy of activation

KW - Lanthanides

KW - Molecular dynamics

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