STUDIES ON LONG-RANGE COUPLINGS BETWEEN 77Se AND 13C IN SOME ARYL SELENIDES, DICHLORIDES, AND SELENOXIDES. THE INVERSE EFFECT ON COUPLINGS IN THE SELENOXIDE FORMATION.

Article abstract of DOI:10.1246/bcsj.56.1661

Long-range coupling constants between **7**7Se and **1**3C in selenoanisole, diphenyl selenide, diphenyl diselenide, and their 2-mono- and 2,2 prime -disubstituted derivatives, selenoxanthone, selenanthrene, dichlorides, and selenoxides were measured to disclose predominant factors governing the magnitude of the coupling. Extraordinary large values for two- and three-bond couplings are found in selenoxanthone. Three factors are operative: the orientational effect, the coordination number, and the effect of ring formation. The last factor accompanies a stronger inverse effect on the coupling of selenoxides than on that of selenides.