115988-72-2Relevant academic research and scientific papers
DYNAMICS OF INTERACTION BETWEEN A 1,9-BIRADICAL AND LANTHANIDE IONS
Wang, Jinfeng,Welsh, Kevin M.,Waterman, Kenneth C.,Fehlner, Paul,Doubleday, Charles,et al.
, p. 3730 - 3732 (1988)
The lifetime of triplet 1,9-biradical derived from 2,10-diphenylcyclodecanone was studied in the presence of lanthanide(III) ions (Ln(3+)) in methanol solvent.The biradical lifetime is greatly decreased in the presence of several of the Ln(3+) ions.Bimolecular rate constants ke for the Ln(3+)-induced biradical decay range from 0 to 2.8 * 1E8 M-1 s-1.The Ln(3+) effect is not due to chemical reaction, since no new products are observed and the product ratio is minimally perturbed.It is proposed that ke represents spin exchange between biradical and Ln(3+).As a model for dipolar electronic relaxation by Ln(3+), a possible alternative mechanism for Ln(3+)-induced biradical decay, proton T1 relaxation times for sodium dodecyl sulfate micelles were measured in the presence of Ln(3+) ions.The pattern of Ln(3+)-induced nuclear relaxation enhancements as a function of Ln(3+) was significantly different from the pattern of ke vs Ln(3+).On the other hand, the known theory of spin exchange accounts qualitatively for the dependence of ke on Ln(3+).The evidence thus suggests spin exchange as the dominant mechanism.
