Theoretical and experimental stimulated nuclear polarization investigation of consecutive biradicals

The characteristic features of stimulated nuclear polarization (SNP) in consecutive short-lived biradicals have been investigated theoretically and experimentally. For calculations of SNP of consecutive biradicals, a model has been developed based on the numerical solution of the stochastic Liouville equation, which accounts explicitly for the distance-dependent exchange interaction and molecular mobility of the biradical chain. The SNP kinetics and spectra of acyl-alkyl and bis(alkyl) biradicals generated upon photolysis of tetramethyl-substituted cycloalkanones with 11–15 carbons in the chain were studied and analyzed in the range of magnetic fields of 11–50 mT.