Tautomer energy comparison
using model chemistry: QCISD/6-31+G**
| formula |
sketch |
Energy (kJ mol-1) |
Name |
difference |
| A |
B |
calculated |
experiment |
A |
B |
| C3H4 |
 |
 |
2 |
7 |
allene |
propyne |
-4 |
| C4H6 |
 |
 |
56 |
49 |
Cyclobutene |
1,3-Butadiene |
6 |
| C4H6 |
 |
|
52 |
51 |
1,2-Butadiene |
1,3-Butadiene |
1 |
| C4H6 |
|
 |
-6 |
-3 |
1,2-Butadiene |
1-Butyne |
-3 |
| C4H6 |
|
 |
13 |
17 |
1,2-Butadiene |
2-Butyne |
-4 |
| C3H6O |
 |
 |
114 |
110 |
Oxetane |
Propanal |
4 |
| C4H8 |
 |
 |
30 |
33 |
cyclobutane |
1-Butene |
-2 |
| C5H8 |
 |
 |
-24 |
-25 |
1,3-Pentadiene, (E)- |
1,4-Pentadiene |
1 |
| C5H8 |
 |
 |
51 |
52 |
1,2-Butadiene, 3-methyl- |
1,3-Butadiene, 2-methyl- |
-1 |
