Methy Vinyl Ketone (MVK) is in the equilibrium condition of two stable conformers, s-trans and s-cis. The spectroscopic identification and SCF-MO calculation (CNDO/2 approach) of MVK were discussed in this paper.
Although UV and NMR spectra were observed as the mean values of two forms, nine conformational peaks were confirmed by IR spectrum.
From the chemical shifts of vinylic protons in NMR, it may be suggested that MVK monomer contains about 24.4% of the s-cis form.
Moreover, ΔH between s-cis and s-trans was (2.4±0.8)×10-1kcal/mol, which is obtained from the change of the chemical shift at temperature of 20°C to 70°C.
The results by CNDO/2 approach on s-cis and s-trans were obviously different each other and supported these spectra data.
