Theoretical and experimental stimulated nuclear polarization investigationof consecutive biradicals

The characteristic features of stimulated nuclear polarization (SNP) in con secutive short-lived biradicals have been investigated theoretically and ex perimentally. For calculations of SNP of consecutive biradicals, a model ha s been developed based on the numerical solution of the stochastic Liouvill e equation, which accounts explicitly for the distance-dependent exchange i nteraction and molecular mobility of the biradical chain. The SNP kinetics and spectra of acyl-alkyl and bis(alkyl) biradicals generated upon photolys is of tetramethyl-substituted cycloalkanones with 11-15 carbons in the chai n were studied and analyzed in the range of magnetic fields of 11-50 mT. (C ) 1999 Published by Elsevier Science B.V. All rights reserved.