National Institute of Standards and Technology
Computational Chemistry Comparison and Benchmark DataBase
Release 17bSeptember 2015
NIST Standard Reference Database 101
IIntroduction
IIExperimental data
IIICalculated data
IVData comparisons
VCost comparisons
VIInput and output files
VIITutorials and Units
VIIILinks to other sites
IXFeedback
XOlder CCCBDB versions
XIIGeometries
XIII Vibrations
XIVReaction data
XVEntropy data
XVIBibliographic data
XVIIIon data
XVIIIBad calculations
XIXIndex of properties
XXH-bond dimers
XXIOddities

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IV.A.4.b.

Tautomer energy comparison

using model chemistry: QCISD/3-21G

formula sketch Energy (kJ mol-1) Name difference
A B calculated experiment A B
C3H4 sketch of allene sketch of propyne 15 7 allene propyne 8
C4H6 sketch of 1,2-Butadiene sketch of 1,3-Butadiene 43 51 1,2-Butadiene 1,3-Butadiene -8
C4H6 sketch of 1,2-Butadiene sketch of 1,3-Butadiene 34 51 1,2-Butadiene 1,3-Butadiene -17
C4H6 sketch of 1,2-Butadiene sketch of 1-Butyne 9 -3 1,2-Butadiene 1-Butyne 12
C4H6 sketch of 1,2-Butadiene sketch of 2-Butyne 26 17 1,2-Butadiene 2-Butyne 9
C4H6 sketch of Cyclobutene sketch of 1,3-Butadiene 77 49 Cyclobutene 1,3-Butadiene 28
C4H6 sketch of Cyclobutene sketch of 1,3-Butadiene 68 49 Cyclobutene 1,3-Butadiene 19
C4H6 sketch of 1-Methylcyclopropene sketch of 1,2-Butadiene 131 82 1-Methylcyclopropene 1,2-Butadiene 49
C4H6 sketch of Methylenecyclopropane sketch of 1-Methylcyclopropene -62 -42 Methylenecyclopropane 1-Methylcyclopropene -20
C3H6O sketch of Oxetane sketch of Propanal 123 110 Oxetane Propanal 13
C3H6O sketch of Oxetane sketch of Propanal 123 110 Oxetane Propanal 13
C4H8 sketch of cyclobutane sketch of 1-Butene 41 33 cyclobutane 1-Butene 9
C4H8 sketch of cyclobutane sketch of 1-Butene 41 33 cyclobutane 1-Butene 9
C4H8 sketch of cyclobutane sketch of 1-Butene 41 33 cyclobutane 1-Butene 9
C4H8 sketch of cyclobutane sketch of 1-Butene 41 33 cyclobutane 1-Butene 9
C4H6S sketch of Thiophene, 2,5-dihydro- sketch of Thiophene, 2,3-dihydro- -8 -4 Thiophene, 2,5-dihydro- Thiophene, 2,3-dihydro- -3
C4H8O sketch of Butanal sketch of Furan, tetrahydro- -30 -29 Butanal Furan, tetrahydro- -0
C5H10 sketch of Cyclopropane, 1,1-dimethyl- sketch of 1-Butene, 2-methyl- 59 29 Cyclopropane, 1,1-dimethyl- 1-Butene, 2-methyl- 30
C5H10 sketch of 1-Butene, 2-methyl- sketch of 2-Butene, 2-methyl- 4 5 1-Butene, 2-methyl- 2-Butene, 2-methyl- -1
C6H8 sketch of 1,4-Cyclohexadiene sketch of 1,3-Cyclohexadiene -1 3 1,4-Cyclohexadiene 1,3-Cyclohexadiene -3