Knowledge Bank

Comparative studies have been made of the infrared and Raman spectra of several compounds of the type [FIGURE] where X is $CH2$ or O and Y is H or $CH3$. The measurements extended over a temperature range from $-150$ to $200\circ C$. These investigations show that most of these substances exist predominantly in the planar s-trans configuration and only in the case of methylvinyl ketone could the presence of s-cis from be positively established. Several deuterated species were also investigated.