Vibrational analysis and conformational study of 3-dimethylamino-2-acetyl propenenitrile and 3-dimethylamino-2-methylsulfonyl propenenitrile

Vibrational spectra revealed that in polar solutions E-DAAPN exists as two conformers with Z or E orientation of acetyl group, the Z conformer being about 2.2±0.3 kJ mol−1 more stable than the E one. The influence of environment polarity on this conformational equilibrium is discussed with respect to the SCRF solvent effect calculations using IPCM and PCM models.