Spectrometric studies and theoretical calculations of some β-ketonitriles

The tautomerism of some β-ketonitriles is investigated by the analysis of their mass spectra and theoretical calculations performed at the MP2/6-31G(d,p) level. The mass spectra of some β-ketonitriles can provide valuable information regarding the keto-enol and nitrile-ketenimine equilibria taking place in the gas phase. The predictive value of this methodology is supported by the influence of the nature and size of substituents on tautomeric equilibria and the rather good correlation existing between the abundance ratios of selected fragments. Results show that the tautomeric equilibria of these bifunctional compounds can be evaluated by mass spectrometry.