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IV.A.4.b.

Tautomer energy comparison

using model chemistry: B3PW91/6-31+G**

formula sketch Energy (kJ mol-1) Name difference
A B calculated experiment A B
C3H4 sketch of allene sketch of propyne -12 7 allene propyne -19
C4H6 sketch of 1,2-Butadiene sketch of 1,3-Butadiene 41 51 1,2-Butadiene 1,3-Butadiene -10
C4H6 sketch of 1,2-Butadiene sketch of 1,3-Butadiene 27 51 1,2-Butadiene 1,3-Butadiene -24
C4H6 sketch of 1,2-Butadiene sketch of 1-Butyne -24 -3 1,2-Butadiene 1-Butyne -21
C4H6 sketch of 1,2-Butadiene sketch of 2-Butyne 6 17 1,2-Butadiene 2-Butyne -10
C4H6 sketch of Cyclobutene sketch of 1,3-Butadiene 42 49 Cyclobutene 1,3-Butadiene -7
C4H6 sketch of Cyclobutene sketch of 1,3-Butadiene 28 49 Cyclobutene 1,3-Butadiene -22
C4H6 sketch of 1-Methylcyclopropene sketch of 1,2-Butadiene 73 82 1-Methylcyclopropene 1,2-Butadiene -9
C4H6 sketch of Methylenecyclopropane sketch of 1-Methylcyclopropene -49 -42 Methylenecyclopropane 1-Methylcyclopropene -7
C3H6O sketch of Oxetane sketch of Propanal 104 110 Oxetane Propanal -6
C4H8 sketch of cyclobutane sketch of 1-Butene 17 33 cyclobutane 1-Butene -15
C3H4O2 sketch of 2-Propenoic acid sketch of β–Propiolactone -27 -29 2-Propenoic acid β–Propiolactone 1
C4H6S sketch of Thiophene, 2,5-dihydro- sketch of Thiophene, 2,3-dihydro- 1 -4 Thiophene, 2,5-dihydro- Thiophene, 2,3-dihydro- 6
C5H8 sketch of 1,3-Pentadiene, (E)- sketch of 1,4-Pentadiene -35 -25 1,3-Pentadiene, (E)- 1,4-Pentadiene -10
C5H8 sketch of 1,3-Pentadiene, (E)- sketch of 1,2-Pentadiene -59 -64 1,3-Pentadiene, (E)- 1,2-Pentadiene 5
C5H8 sketch of 1,2-Butadiene, 3-methyl- sketch of 1,3-Butadiene, 2-methyl- 41 52 1,2-Butadiene, 3-methyl- 1,3-Butadiene, 2-methyl- -11
C4H8O sketch of Butanal sketch of Furan, tetrahydro- -26 -29 Butanal Furan, tetrahydro- 3
C5H10 sketch of 1-Butene, 2-methyl- sketch of 2-Butene, 2-methyl- 11 5 1-Butene, 2-methyl- 2-Butene, 2-methyl- 6
C5H10 sketch of Cyclopropane, 1,1-dimethyl- sketch of 1-Butene, 2-methyl- 17 29 Cyclopropane, 1,1-dimethyl- 1-Butene, 2-methyl- -12
C6H8 sketch of 1,4-Cyclohexadiene sketch of 1,3-Cyclohexadiene 1 3 1,4-Cyclohexadiene 1,3-Cyclohexadiene -2