Linked Life Data

9615409

Source:http://linkedlifedata.com/resource/pubmed/id/9615409

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
1998-6-19
pubmed:abstractText
Measurements of 7Li nuclear spin-lattice relaxation times are made at applied magnetic field strengths from 0.25 mT to 7.05 T, in order to determine directly the form of the frequency-dependent spectral densities that modulate relaxation. This magnetic resonance dispersion (MRD) technique provides detailed information regarding molecular dynamics down to the picosecond time scale. 7Li MRD measurements made on aqueous lithium ion in the presence of small concentrations of nitroxide free radicals give direct evidence supporting the formation of a coordination complex. The dipole-dipole electron-nuclear coupling is modulated by both translational and rotational diffusive motions, and both of these contributions are resolved. However, scalar coupling arising from the presence of paramagnetic electron spin density at the nucleus dominates the nuclear relaxation. Changes in the pH and free radical moiety are compared with dynamical variables, geometric constraints, and formation constants obtained from a model of nuclear relaxation. The calculated bimolecular formation constants are on the order of 2 x 10(-3) M-1, and the relative accuracy of this parameter is tested.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
1090-7807
pubmed:author
pubmed:issnType
Print
pubmed:volume
132
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
19-24
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1998
pubmed:articleTitle
Magnetic relaxation dispersion of 7Li. II. Complex formation with nitroxides in the aqueous phase.
pubmed:affiliation
Department of Chemistry, University of Virginia, Charlottesville 22901, USA.
pubmed:publicationType
Journal Article, Comparative Study, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't