Joint analysis of ESR lineshapes and (1)H NMRD profiles of DOTA-Gd derivatives by means of the slow motion theory
2011 (English)In: Journal of Chemical Physics, ISSN 0021-9606, E-ISSN 1089-7690, Vol. 134, no 2, 024508- p.Article in journal (Refereed) Published
The Swedish slow motion theory [Nilsson and Kowalewski, J. Magn. Reson. 146, 345 (2000)] applied so far to Nuclear Magnetic Relaxation Dispersion (NMRD) profiles for solutions of transition metal ion complexes has been extended to ESR spectral analysis, including in addition g-tensor anisotropy effects. The extended theory has been applied to interpret in a consistent way (within one set of parameters) NMRD profiles and ESR spectra at 95 and 237 GHz for two Gd(III) complexes denoted as P760 and P792 (hydrophilic derivatives of DOTA-Gd, with molecular masses of 5.6 and 6.5 kDa, respectively). The goal is to verify the applicability of the commonly used pseudorotational model of the transient zero field splitting (ZFS). According to this model the transient ZFS is described by a tensor of a constant amplitude, defined in its own principal axes system, which changes its orientation with respect to the laboratory frame according to the isotropic diffusion equation with a characteristic time constant (correlation time) reflecting the time scale of the distortional motion. This unified interpretation of the ESR and NMRD leads to reasonable agreement with the experimental data, indicating that the pseudorotational model indeed captures the essential features of the electron spin dynamics.
Place, publisher, year, edition, pages
2011. Vol. 134, no 2, 024508- p.
Atom and Molecular Physics and Optics
IdentifiersURN: urn:nbn:se:su:diva-67360DOI: 10.1063/1.3516590ISI: 000286471900049OAI: oai:DiVA.org:su-67360DiVA: diva2:470153
authorCount :72011-12-282011-12-282011-12-28Bibliographically approved