Einfluß von Kohärenzeffekten auf die Linienformen im ENDOR-Spektrum des Perinaphthenyl-Radikals / Influence of Coherence Effects On Line Shapes in the ENDOR Spectrum of the Perinaphthenyl Radical

A cw high-power ENDOR spectrometer is described. Freed's theory of coherence effects on ENDOR line shapes of free radicals in solution was tested with cw NMR fields up to 30 Gauss. The neutral radical Perinaphthenyl (PNT) with groups of three and six equivalent protons served as example. A satisfactory agreement with the theory was found, even in quantitative terms. Very reasonable values for relaxation times T1e , T2e and T1n of the PNT could be determined by fitting Te-1/We, Wn/We and using measured values for BMW, BNMR and the EPR line width.

Electron nuclear double resonance of divalent thulium in calcium fluoride

An investigation of the ground state of 169 Tm 2+ in CaF 2 has been carried out by the endor method. The positions of excited crystal field states were known accurately from the work of Kiss (1962) and with this information it was possible to obtain a value of μ n = (─)0·234 ± 0·003 n. m. for the nuclear moment of 169 Tm which may be compared with the atomic beam value of μ n = ─0·229 ± 0·003 n. m. (Ritter 1962). The hyperfine interactions of the Tm 2+ ion with the four nearest fluorine shells have been measured. Both the thulium and fluorine endor line widths were investigated at X band and at K band and the results are discussed.