Organoselenium Chemistry. Addition of Tolueneselenenyl Chloride to Ethylene: Concerning the Reported Isolation of a Stable Episelenurane

Abstract

The addition of ethylene to solutions of 4-tolueneselenenyl chloride (ArSeCl) gives initially the selenide dichloride 5. Only after more than 20% of the theoretical amount of ethylene has been added does the normal adduct appear. This anomaly is caused by the reversible reaction of the normal adduct 4 with ArSeCl, giving diselenide and 5. The episelenurane 1 reported as a product of the reaction of ArSeCl with ethylene appears to be actually the dichloride 5. Even at low temperature no evidence for the formation of a stable episelenurane was obtained. The 13C n.m.r. spectra of several organoselenium compounds are reported, including a number of selenium-77 carbon-13 coupling constants.