Diacetylmethylenediphenylselenurane, 1, a selenium ylide, was prepared by the reaction of diphenylselenium dichloride with sodium acetylacetonate in methanol solution. The nmr spectrum showed a methyl singlet at 2.43 ppm. X-Ray analysis confirmed the structure as an ylide and showed that the configuration at selenium was pyramidal with Se lying 0.78 A out of the plane of its three bonded atoms. Low-temperature nmr studies show that the equilibration of the two methyl groups proceeds via an energy barrier of <10 kcal/mol. The crystals of 1 are monoclinic with a = 13.297 ( 7), b = 13.418 (6), c = 9.112 (5) Á, and ß = 111.7 (1)°; the space group is P2Jc and there are four molecules of Ci7Hie02Se in the unit cell.
The structure of 3,4-ethano-2,3,4,5-tetrahydro-2,5-bisphenylimino-l,6,6a,Srv-trithia-3,4-diazapentalene (I) has been confirmed by X-ray crystallography.THE structure (I), assigned1 to the yellow product obtained by treatment of the isothiouronium salt (I1 ; n = 1) with aqueous sodium hydrogen carbonate and phenyl isothiocyanate, has been confirmed by X-ray crystallography.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.