ESR spectroscopic investigation of some 4-substituted 1,3,2-dithiazolyl and 2,3,1-dithiazolyl radicals

✍ Scribed by Yuen-Li Chung; Shirley A. Fairhurst; Duncan G. Gillies; Keith F. Preston; Leslie H. Sutcliffe

• Publisher: John Wiley and Sons
• Year: 2005
• Tongue: English
• Weight: 496 KB
• Volume: 30
• Category: Article
• ISSN: 0749-1581
• DOI: 10.1002/mrc.1260300717

✦ Synopsis

Abstract

Further information has been obtained on the electronic structure of 1,3,2‐dithiazol‐2‐yl radicals. The structure has been well characterized previously except for positions 4 and 5 in the
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ring. We have obtained solution and powder ESR spectra of radicals substituted with ^13^C in both positions and of radicals substituted with nitrogen or phosphorus in the 4‐position. It is probably the first time that a compound has been prepared containing the
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ring. Two especially interesting facts emerged from the ESR spectra of these 1,3,2‐dithiazolyl radicals: the ^13^C‐substituted radical has a considerable amount of p spin density in the plane of the ring and the phosphorussubstituted radical has a very low unpaired spin density at the phosphorus atom. It is known that 1,3,2,4‐dithiadiazolyl radicals isomerize readily by photolysis to the symmetrical 2,3,1,4‐dithiadiazolyl radicals; we attempted the same reaction with Bu^t^
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and a new radical was produced that we have been unable to identify.