Tautomer energy comparison
using model chemistry: mPW1PW91/3-21G
| formula |
sketch |
Energy (kJ mol-1) |
Name |
difference |
| A |
B |
calculated |
experiment |
A |
B |
| C3H4 |
 |
 |
-4 |
7 |
allene |
propyne |
-10 |
| C4H6 |
 |
 |
38 |
51 |
1,2-Butadiene |
1,3-Butadiene |
-14 |
| C4H6 |
|
 |
-13 |
-3 |
1,2-Butadiene |
1-Butyne |
-10 |
| C4H6 |
|
 |
14 |
17 |
1,2-Butadiene |
2-Butyne |
-3 |
| C4H6 |
 |
|
44 |
49 |
Cyclobutene |
1,3-Butadiene |
-5 |
| C4H6 |
 |
|
107 |
82 |
1-Methylcyclopropene |
1,2-Butadiene |
25 |
| C4H6 |
 |
|
-63 |
-42 |
Methylenecyclopropane |
1-Methylcyclopropene |
-22 |
| C3H6O |
 |
 |
100 |
110 |
Oxetane |
Propanal |
-10 |
| C4H8 |
 |
 |
12 |
33 |
cyclobutane |
1-Butene |
-21 |
| C3H4O2 |
 |
 |
-16 |
-29 |
2-Propenoic acid |
β–Propiolactone |
13 |
| C4H6S |
 |
 |
-6 |
-4 |
Thiophene, 2,5-dihydro- |
Thiophene, 2,3-dihydro- |
-2 |
| C5H8 |
 |
 |
-26 |
-25 |
1,3-Pentadiene, (E)- |
1,4-Pentadiene |
-1 |
| C5H8 |
|
 |
-52 |
-64 |
1,3-Pentadiene, (E)- |
1,2-Pentadiene |
13 |
| C5H8 |
 |
 |
37 |
52 |
1,2-Butadiene, 3-methyl- |
1,3-Butadiene, 2-methyl- |
-15 |
| C4H8O |
 |
 |
-0 |
-29 |
Butanal |
Furan, tetrahydro- |
29 |
| C5H10 |
 |
 |
8 |
5 |
1-Butene, 2-methyl- |
2-Butene, 2-methyl- |
3 |
| C6H8 |
 |
 |
2 |
3 |
1,4-Cyclohexadiene |
1,3-Cyclohexadiene |
-0 |
