ODMR determination of the zero field splitting parameters of a conjugated enone

✍ Scribed by C.R. Jones; F. Pappano; A.H. Maki; D.R. Kearns

• Publisher: Elsevier Science
• Year: 1972
• Tongue: English
• Weight: 335 KB
• Volume: 13
• Category: Article
• ISSN: 0009-2614
• DOI: 10.1016/0009-2614(72)85001-2

✦ Synopsis

We have observed the optically-detected ESR transitions of the steroidal enone testosterone acetate at zero field and found the zerofield splitting (ZFS) parameters to be !.DI -0.28 cm-' and 18'1 = 0.01 cm-'_ Approximate theoretical calculations suggest that. there are at least three important contributions to the ZFS; spin-spin dipolar interaction, spin-orbit coupling of the emitting 3(n,r*) state with the 3(n,rr* ) state, and spin-orbit coupling of the 3(rr,rr*) state with the '(n,rr*) state. Thus the calculated ZFS parameters of D = -0.46 &II-' and E' = -0.014 cm-' represent a delicate balance of these three effects. Bemuse of the large spin-orbit couphng effects the ZFS parameters of cnone 3(~,~*) and 3(n,n*) states, and perhaps ketones in general, depend stra,xly on the separation between

(n,rr) and (n,n) states. This is a complicating feature which may make it difficult to use ZFS parameters to assign the orbita: character of ketone triplet states.