Static zero field splitting effects on the electronic relaxation of paramagnetic metal ion complexes in solution
- 15 November 2000
- journal article
- Published by AIP Publishing in The Journal of Chemical Physics
- Vol. 113 (19) , 8724-8735
- https://doi.org/10.1063/1.1289882
Abstract
A general theory of the electronic relaxation of an S state complexed paramagnetic metal ion (Mn2+, Gd3+) in solution is developed. Contrarily to the usual assumption, the electronic relaxation is not only due to the effects of the transient zero field splitting, but is strongly influenced by the static crystal field effect which is modulated by the random Brownian rotation of the complex. The electron paramagnetic resonance measured linewidths of three Gd3+ (S=7/2) complexes at various temperatures and fields [D. H. Powell J. Am. Chem. Soc. 118, 9333 (1996)] are well interpreted in the framework of this model and show the contributions of both mechanisms. The fitted crystal field parameters, the correlation times, and the activation energies are in good agreement with their expected values from the underlying processes. Moreover, our interpretation does not require the addition of any field independent contribution to the linewidth like the spin-rotation mechanism. The longitudinal relaxation function is well approximated using a single relaxation time, whereas the transverse relaxation function is a superposition of four decreasing exponentials. (C) 2000 American Institute of Physics. [S0021-9606(00)50537-6]Keywords
This publication has 14 references indexed in Scilit:
- NMR approach of the electronic properties of the hydrated trivalent rare earth ions in solutionThe European Physical Journal D, 1999
- Multi-frequency EPR determination of zero field splitting of high spin species in liquids: Gd(III) chelates in waterMolecular Physics, 1998
- Nuclear and electronic relaxation in lanthanide solutions: (CH3)4N+/Gd3+ repulsive ion pair in D2OChemical Physics Letters, 1998
- Structural and Dynamic Parameters Obtained from 17O NMR, EPR, and NMRD Studies of Monomeric and Dimeric Gd3+ Complexes of Interest in Magnetic Resonance Imaging: An Integrated and Theoretically Self-Consistent Approach1Journal of the American Chemical Society, 1996
- Molecular Dynamics Simulation Study of Lanthanide Ions Ln3+ in Aqueous Solution. Analysis of the Structure of the First Hydration Shell and of the Origin of Symmetry FluctuationsThe Journal of Physical Chemistry, 1995
- Water-exchange, electronic relaxation, and rotational dynamics of the MRI contrast agent [Gd(DTPA-BMA)(H2O)] in aqueous solution: a variable pressure, temperature, and magnetic field oxygen-17 NMR studyThe Journal of Physical Chemistry, 1994
- Magnetic‐Field‐Dependent Electronic Relaxation of Gd3+ in Aqueous Solutions of the Complexes [Gd(H2O)8]3+, [Gd(propane‐1,3‐diamine‐N,N,N′,N′‐tetraacetate)(H2O)2]−, and [Gd(N,N′‐bis[(N‐methylcarbamoyl)methyl]‐3‐azapentane‐1,5‐diamine‐3,N,N′‐triacetate)(H2O)] of interest in magnetic‐resonance imagingHelvetica Chimica Acta, 1993
- The application of tensor operators in the analysis of EPR and ENDOR spectraPhysica Status Solidi (a), 1972
- Electronic and nuclear relaxation in solutions of transition metal ions with spinS=3/2 and 5/2Molecular Physics, 1971
- Paramagnetic Resonance Absorption in Gadolinium TrichlorideProceedings of the Physical Society. Section B, 1957