64045-87-0Relevant articles and documents
Sytheses and ENDOR Studies of Selectively Deuterated Galvinoxyl Radicals. Complete Determination of the 13C Hyperfine Coupling Constants of Coppingers's Radical
Kirste, Burkhard,Kurrek, Harry,Sordo, Magdalena
, p. 1782 - 1797 (2007/10/02)
The synthesis of selectively deuterated galvinols is described.Oxidation results in the formation of the respective galvinoxyl free radicals, e.g., Coppinger's radical and Yang's biradical.It is shown that 13C ENDOR signals can be detected for the doublet radicals without 13C labelling, i.e., in natural abundance.The complete set of 13C hyperfine coupling constants of Coppinger's radical could be determined.The ENDOR study of selectively deuterated Yang's biradical in a glassy matrix allowed an unambiguous assignment of the signals to molecular positions, and conclusions with respect to the symmetry of the radical and the hindered rotation of the tert-butyl groups could be drawn.Randomly oriented bisgalvinoxyl biradicals in the triplet spin state give rise to sharp ENDOR lines at the free nuclear Zeeman frequencies due to NMR transitions in the MS=0 electron spin manifold, and it is demonstrated that the respective 2H ENDOR lines show quadrupole splittings.