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IV.A.4.b.

Tautomer energy comparison

using model chemistry: MP2/CEP-31G*

formula sketch Energy (kJ mol-1) Name difference
A B calculated experiment A B
C3H4 sketch of allene sketch of propyne 18 7 allene propyne 11
C4H6 sketch of 1-Methylcyclopropene sketch of 1,2-Butadiene 49 82 1-Methylcyclopropene 1,2-Butadiene -33
C4H6 sketch of Methylenecyclopropane sketch of 1-Methylcyclopropene -40 -42 Methylenecyclopropane 1-Methylcyclopropene 2
C4H6 sketch of Cyclobutene sketch of 1,3-Butadiene 26 49 Cyclobutene 1,3-Butadiene -23
C4H6 sketch of Cyclobutene sketch of 1,3-Butadiene 11 49 Cyclobutene 1,3-Butadiene -38
C4H6 sketch of 1,2-Butadiene sketch of 2-Butyne 22 17 1,2-Butadiene 2-Butyne 5
C4H6 sketch of 1,2-Butadiene sketch of 1-Butyne 8 -3 1,2-Butadiene 1-Butyne 11
C4H6 sketch of 1,2-Butadiene sketch of 1,3-Butadiene 63 51 1,2-Butadiene 1,3-Butadiene 12
C4H6 sketch of 1,2-Butadiene sketch of 1,3-Butadiene 48 51 1,2-Butadiene 1,3-Butadiene -3
C4H8 sketch of cyclobutane sketch of 1-Butene 1 33 cyclobutane 1-Butene -32
C3H4O2 sketch of 2-Propenoic acid sketch of β–Propiolactone -5 -29 2-Propenoic acid β–Propiolactone 24
C4H6S sketch of Thiophene, 2,5-dihydro- sketch of Thiophene, 2,3-dihydro- 5 -4 Thiophene, 2,5-dihydro- Thiophene, 2,3-dihydro- 9
C5H8 sketch of 1,2-Butadiene, 3-methyl- sketch of 1,3-Butadiene, 2-methyl- 61 52 1,2-Butadiene, 3-methyl- 1,3-Butadiene, 2-methyl- 10
C5H8 sketch of 1,3-Pentadiene, (E)- sketch of 1,2-Pentadiene -75 -64 1,3-Pentadiene, (E)- 1,2-Pentadiene -11
C5H8 sketch of 1,3-Pentadiene, (E)- sketch of 1,4-Pentadiene -31 -25 1,3-Pentadiene, (E)- 1,4-Pentadiene -6
C4H8O sketch of Butanal sketch of Furan, tetrahydro- -25 -29 Butanal Furan, tetrahydro- 5
C5H10 sketch of Cyclopropane, 1,1-dimethyl- sketch of 1-Butene, 2-methyl- 5 29 Cyclopropane, 1,1-dimethyl- 1-Butene, 2-methyl- -24
C5H10 sketch of 1-Butene, 2-methyl- sketch of 2-Butene, 2-methyl- 6 5 1-Butene, 2-methyl- 2-Butene, 2-methyl- 0
C6H8 sketch of 1,4-Cyclohexadiene sketch of 1,3-Cyclohexadiene 10 3 1,4-Cyclohexadiene 1,3-Cyclohexadiene 7