[Study on ultraviolet spectra of alpha,alpha'-dioxoketene cyclic S,S-acetals].

The characteristics of ultraviolet spectra of five alpha,alpha'-dioxoketene cyclis,s,s-acetals (N,N-acetals) have been studied in different solvent, on the basis of last paper. And the character of ultraviolet spectra of sulfur-containing compounds and nitrogen-containing compound was compared in the same solvent, the changing rules with the change of chemical structure have been indicated. It is specially important that the character of such as this conjugated system was studied, however it almost did not do before. And the this can used in studies afterwards.