Spectrometric Study of the Nitrile-Ketenimine Tautomerism

Table 1

Heats of formation and relative stabilities of the tautomeric forms of ethyl-4,4-dicyano-3-methyl-3-butenoate by AM1 calculations.

Tautomer		Δ Hf, kcal mol^−1	ΔΔHf, kcal mol^−1
I		−24,18846	0
II		−6,2391	17,94936
III		−8,38831	15,80015
IV		3,558174	27,746634
V		−8,176637	16,011823
VI		−8,175188	16,013272
VII		17,81065	41,99911
VIII		17,98366	42,17212